Real Washing Machines are those in which the water is storming. Welcome to Washer Rama Museum WEB Museum, here you will see some Obsolete Old Washing Machines of an era were washing clothes was real and the fun of looking at it was an attractive and relaxing good time loosing and many schematic diagrams of them........Just Surf.....

How to use the site

On this site you will find pictures and information about some of the electrical and mecanichal relics that the Frank Sharp Private museum has accumulated over the years .

There are lots of vintage electrical and electronic items that have not survived well or even completely disappeared and forgotten.

Or are not being collected nowadays in proportion to their significance or prevalence in their heyday, this is bad and the main part of the death land. The heavy, ugly sarcophagus; models with few endearing qualities, devices that have some over-riding disadvantage to ownership such as heavy weight,toxicity or inflated value when dismantled, tend to be under-represented by all but the most comprehensive collections and museums. They get relegated to the bottom of the wants list, derided as 'more trouble than they are worth', or just forgotten entirely. As a result, I started to notice gaps in the current representation of the history of electronic and electrical technology to the interested member of the public.

Following this idea around a bit, convinced me that a collection of the peculiar alone could not hope to survive on its own merits, but a museum that gave equal display space to the popular and the unpopular, would bring things to the attention of the average person that he has previously passed by or been shielded from. It's a matter of culture. From this, the Washer Rama Web Museum concept developed and all my other things too. It's an open platform for all electrical Electronic TV technology to have its few, but NOT last, moments of fame in a working, hand-on environment. We'll never own Colossus or Faraday's first transformer, but I can show things that you can't see at the Science Museum, and let you play with things that the Smithsonian can't allow people to touch, because my remit is different.

There was a society once that was the polar opposite of our disposable, junk society. A whole nation was built on the idea of placing quality before quantity in all things. The goal was not “more and newer,” but “better and higher" .This attitude was reflected not only in the manufacturing of material goods, but also in the realms of art and architecture, as well as in the social fabric of everyday life. The goal was for each new cohort of children to stand on a higher level than the preceding cohort: they were to be healthier, stronger, more intelligent, and more vibrant in every way.

The society that prioritized human, social and material quality is a Winner. Truly, it is the high point of all Western civilization. Consequently, its defeat meant the defeat of civilization itself.Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

OLD, but ORIGINAL, Well made, Funny, Not remotely controlled............. and not Made in CHINA.

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- If you landed here via any Search Engine, you will get what you searched for and you can search more using the search this blog feature provided by Google. You can visit more posts scrolling the right blog archive of all posts of the month/year,or you can click on the main photo-page to start from the main page. If doing so it starts from the most recent post to the older post doing simple clicking on the Older Post button on the bottom of each page after reading , post after post.

You can even visit all posts, time to time, reaching the bottom end of each page then click on the Older Post button.

- If you arrived here at the main page via bookmark you can visit all the site scrolling the right blog archive of all posts of the month/year pointing were you want , or more simple You can even visit all blog posts, from newer to older, clicking at the end of each bottom page on the Older Post button.So you can see all the blog/site content surfing all pages in it.

- The search this blog feature provided by Google is a real search engine. If you're pointing particular things it will search IT for you; or you can place a brand name in the search query at your choice and visit all results page by page. It's useful since the content of the site is very large.

Note that if you don't find what you searched for, try it after a period of time; the site is a never ending job !

Technology has made us leap in terms of saving time and efforts. From the conventional pounding of clothes on the rock to the modern cubical white boxes which have several buttons for washing your clothes delicately or permanent press, we have come far from primitive hiccups of civilization.

Unlike other collector's items like watches, radios or cars, antique washing machine models do not allure the collectors, who try to avoid them as much as they can. One of the main reasons is that they are difficult to maintain.

1900 to 1935 saw the advent of old washing machines that were powered by gasoline or electric motors. Gasoline was hazardous and had environmental issues.

Before 1900, antique washing machines were actually run by people. But, invention of internal combustion engine and electric motor changed the scenario and electric powered washing machines became popular. Since the old washing machines did not have on-off switch, if the clothes or hand of the user was caught in it, the electric chord had to be pulled out or the user could lose her anatomy. Basically, the safety mechanism was primeval.

History of antique washing machine can be traced back to 1800's when rotary washing machines were invented. Then in 1908, Hurley in Chicago introduced Thor - a vintage washing machine that comprised of a galvanized tub and an electric motor. The tub was wooden and turned 8 revolutions before reversing. It was designed by Fisher.

In 1893, Maytag Corporation started manufacturing washing machines and in 1907 they introduced a wooden tub in it. Upton Machine Company or Whirlpool started in 1911 in Michigan. It manufactured electric motor driven wringer washers.

In 1920 rocker type machines became extremely popular. Judd rocker was amongst them but this washing machine did not have wringer safety release. There was no earth and the terminals were not insulated. Later, Horton Company in Indiana started manufacturing electric machines, which featured a powered wringer. Additionally, it had a safety release.

J. T. Winans got patent for washing machine that had pulley, which was driven by a water motor. The water motor was belted to the pulley and this was connected to a tap. The water powered motors did not become popular and eventually the company shifted its focus to electrical powered washers.

One of the most interesting antique washing machines belonging to early 1900s was the Laun-Dry-Ette which was manufactured by Home Specialty Company, Ohio. There was no wringer present in it but it comprised of two cups (having an agitator), which produced a twisting motion for better cleaning. This old model is a darling of many vintage washing machine collectors. According to estimation, there were more than 1000 companies in the early 1900s which were manufacturing washing machines. Most of them were small scale companies, but they all had resources to manufacture electric washers.

In 1691, first British patent was issued for the category of Washing and Wringing Machines.

In 1782, British patent for a rotating drum washer was issued to Henry Sidgier. Nathanial Briggs was the first American to get the patent in this category. Louis Goldenberg of New Jersey invented electric washer in the early 1900s. Since he was employed with Ford, all inventions created by him during that time belonged to Ford.

In 1928, US sales increased to more than 900,000 units, but the sales dipped by 1932 to about 600,000 units only, due to Great Depression.

In 1930s spin dryers were introduced and the entire mechanism was hemmed in a cabinet. Manufacturers started paying lot of attention to safety issues. Spin dryers replaced the electric powered wringers. Almost 60% of the households in US owned electric washing machines in 1940s.

In 1937, Bendix was issued a patent for automatic washing machine. The machine had to be anchored or fixed to the ground so that it didn't shift while functioning. Bendix Deluxe was introduced in 1947 and it was a front loading machine. It was priced at $250. GE was the first company that introduced top load washing machines.

1940s and 1950s saw proliferation of washing machines that were mainly top loading. Some companies manufactured laundry machines which were semi-automatic. The user was supposed to intervene with the wash cycle in order to wring and rinse the clothes.

Every OLD Washing Machine saved let revive knowledge, noise, thoughts, wash engineering, moments of the past life which will never return again.........

These were the days when some washing machines were more like machine tools and bristled with levers and gears. There was a sense of occasion when they were powered up and then helping to guide soaking sheets through those powerful rollers with torrents of soapy steaming water (roughly) pouring back into the tub.

Many contemporary appliances would not have this level of staying power, many would ware out or require major services within just five years and of course, there is that perennial bug bear of planned obsolescence where components our deliberately designed to fail or manufactured with limited edition specificities.

.......The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory.....

Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

Tuesday, July 2, 2013

IGNIS K12 (PHILIPS) AWF627/IG P.M. SYSTEM INTERNAL VIEW.

The IGNIS K12 (PHILIPS) AWF627/IG P.M. SYSTEM was first Electronic driven motor washing machine featuring a control circuit for permanent magnet (PM SYSTEM) or constant excitation direct
current motors, particularly for washing machines, characterized by a circuit for regulating the rotational speed of a DC motor. In the
modern actual known circuit, a tachometer dynamo is fixed onto the shaft of said
motor, said dynamo generating a signal which is proportional to the
motor rotational speed and is fed to an electronic circuit which acts on
the motor to regulate its speed when required.

In the case of tachometer dynamos, their cost is relatively high and their installation is often laborious and costly.

The
main object of the present invention featured in the IGNIS K12 (PHILIPS) AWF627/IG P.M. SYSTEM is therefore to provide an
electric motor control circuit which operates accurately without such
costly dynamo.

A further object is to provide an electric motor
control circuit which enables the motor to operate substantially at
constant power within determined limits of torque and rotational speed for safety reason.

During the motor drive time, motor velocity is proportional to the
applied energizing voltage for constant loads. As the load of the motor
changes the motor velocity will be controlled as a function of applied
energizing voltage by sensing the back emf and comparing the back emf
signal with a commanded motor velocity signal. By controlling the motor
with the back emf, it is thus possible to have a very precise and constant
motor velocity for changing loads by varying the level of applied
energizing voltage. An advantage of the present invention is thus to
provide velocity regulation of a motor that is reasonably constant for a
commanded input signal, even though the motor may inherently have poor
speed regulation if constant voltage is applied because of D.C. motor. The amount of power a motor is required to deliver has
little effect on motor velocity.To control motor velocity with the
Control Unit of the present
invention the behavior of a rotating armature in a field to generate a
back emf is utilized. If the armature isn't moving through the field,
then there is no back emf and the level of any generated back emf is an
immediate indication of the operation of the motor (In example when NO
self restart of the drum is mandatory performed when stopped during
distribution / spind-drain and or spinning). The Control Unit of the
present invention does not rely on a signal provided by an independent
generator, but rather utilizes the basic operation of the motor. There
is also no reliance on the variation in armature resistance, which as
explained, may vary with armature construction. Furthermore the speed of
the motor is resulting as indipendent of the Mains supply voltage for the
aformementioned features.

The control circuit constructed as briefly described is mainly composed by a command circuit, a control circuit and a power circuit with diodes and thyristors and this circuit complex composition enables the motor rotational
speed to be measured as a function of the voltage taken across the motor
terminals with due allowance made for the armature losses arising in
the motor. In this manner the regulation of said rotational speed is
much highly more accurate under any load condition than that which can be
obtained by known electric motor control devices and/or circuits. In
addition the circuit described in the present patent prevents the motor
absorbing mains power to any extent which could lead to mechanical
instability of the washing machine.

The machine IGNIS K12 (PHILIPS) AWF627/IG P.M. SYSTEM is illustrated in the figures but typically it
can comprise a drum mounted on a shaft in bearings so as to be rotatable
on a horizontal axis within a liquid containing cylinder which is
suspended by means of cooperating springs and dampers within an outer
cabinet. A DC electric drive motor of the series-type is secured to the
liquid containing cylinder and is drivingly connected by means of a `V`
or multi-V belt-drive system to a pulley wheel secured to the drum shaft
outside the liquid cylinder. The system is such that the drum is
rotated at a speed below the motor speed and in a fixed relationship of
say 1:10 or thereabout. Liquid may be supplied to the cylinder through
an electromagnetically actuated inlet valve and removed by an electric
motor-driven pump. Liquid in the cylinder may be heated by an electric
sheathed wire heating element mounted in a lower wall of the cylinder,
the heating element being disposed within the cylinder.

In
operation of the washing machine its various functions are sequentially
controlled by a program controller comprising a synchronous electric
timer motor actuating, via a stepping linkage, a number of cams and
hence switches which control the supply of electrical power to the
various parts of the machine in sequence so as to cause a particular
program of operations to be performed on clothes placed in the drum, and
a solid state switching circuit, also controlled by the timer motor for
the drive motor of the machine, which controls the speed and
acceleration of the drum motor.

This invention relates to clothes-washing and spin-drying machines and
relates especially though not exclusively to such machines of the type
in which clothes can be washed in a drum by means of a tumbling action
effected by rotating the drum about a horizontal or at least inclined
axis at a relatively low speed in the presence of washing liquid and can
subsequently be dried by a spinning operation achieved by rotating the
drum about the same axis at a comparatively high speed.

A
problem associated with such washing and spin-drying machines is the
prevention of excessive out of balance forces on the drum during
high-speed spinning due to clothes accumulating at one point in the
drum. With lower spinning speeds the problem can be overcome by
incorporating a suspension for the outer container of such a design that
out of balance forces are absorbed. However, at higher spinning speeds,
which are, in any event, desirable for the successful drying of the
clothes, this solution is not practicable and arrangements must be made
to ensure that the clothes drum is not excessively out of balance during
such high-speed rotation. This may be achieved by making the clothes
drum such that it is self-balancing-- but that reduces the possible size
and hence the capacity of the drum. Alternatively it can be arranged
that whenever the clothes drum is required to rotate at a high spinning
speed this operation is preceded by rotation of the drum at a low
washing speed in the same direction. This solution is not entirely
satisfactory, however, as the speed for washing the clothes must be low
enough to cause the clothes to tumble and not cling to the drum wall,
i.e., the centrifugal force on the clothes must be less than the
gravitational force, and as a result the clothes are not evenly
distributed around the drum wall, as is desired, if the drum is to be in
a balanced condition for the subsequent high-speed spinning operation.

It
is therefore desirable that the drum be rotated at a speed intermediate
the tumbling speed and the spinning speed for a short time prior to
spinning the drum at high speed in order to ensure that the clothes
distribute themselves equally around the internal periphery of the drum
in a balanced manner. This has been achieved, for example, by providing a
drive motor for the drum capable of energization at three speeds, these
speeds being selected by a control arrangement for the machine such
that, on termination of a tumbling action provided by rotation of the
motor at its lowest speed the spin action provided by the motor rotating
at its highest speed is preceded by a short period of rotation at an
intermediate speed where the weight of the clothes is just balanced by
the centrifugal force on the clothes at this speed, the desired result
being that the clothes cease to tumble within the drum and contact the
inner peripheral wall of the drum in a balanced manner. The drive motor
is then accelerated to its highest (spinning) speed. A problem inherent
in this arrangement is that there is no certainty that the clothes will
distribute themselves in a balanced manner in the drum during the period
of rotation at the intermediate speed, as the comparatively rapid
acceleration of the drum from tumbling speed to this intermediate speed
tends to fling the clothes abruptly outwards to the wall of the drum in
the pattern of distribution which they adopt for the previous tumbling
operation (which is very rarely uniform). As a result of this the
acceleration to spinning speed results in large out of balance forces on
the drum.

In a preferred form of the invention design for a combined washing and
spin-drying machine a common DC series electric motor is provided for
driving the clothes drum both for washing and for spin drying, and the
control means includes a motor speed control circuit having means for
generating a series of electric pulses of which the conduction angle or
mark to space ratio determines the power supply to the motor, and said
control means includes time-dependent means for varying said conduction
angle or mark to space ratio in such a way as to produce said different
accelerations.

Conveniently a controlled semiconductor rectifier
device such as a thyristor is provided in series with the electric
motor with respect to input terminals which are arranged to be connected
to an alternating current supply, electric pulses being arranged to be
applied to the gate of the device in appropriate half-cycles of the
alternating current supply to fire the device and cause driving power to
be supplied to the motor.

The control means in such a case is
conveniently formed with solid state control elements, in particular
transistors, so connected and arranged as to control the conduction
angle or mark-to-space ratio of the pulses applied to the motor from the
semiconductor rectifier device.

The control means preferably
also includes feedback means which normally tend to maintain the motor
rotating with a selected constant slow speed, said time-dependent means
being arranged to override the feedback means when a spin drying
operation is initiated.

It will be understood that the invention
also includes within its scope control units for controlling the speed
of an electric motor driving the clothes drum of a clothes-washing and
spin-drying machine or a spin-drying machine in accordance with the
invention.

This invention relates to clothes-washing and spin-drying machines and
relates especially though not exclusively to such machines of the type
in which clothes can be washed in a drum by means of a tumbling action
effected by rotating the drum about a horizontal or at least inclined
axis at a relatively low speed in the presence of washing liquid and can
subsequently be dried by a spinning operation achieved by rotating the
drum about the same axis at a comparatively high speed.

A
problem associated with such washing and spin-drying machines is the
prevention of excessive out of balance forces on the drum during
high-speed spinning due to clothes accumulating at one point in the
drum. With lower spinning speeds the problem can be overcome by
incorporating a suspension for the outer container of such a design that
out of balance forces are absorbed. However, at higher spinning speeds,
which are, in any event, desirable for the successful drying of the
clothes, this solution is not practicable and arrangements must be made
to ensure that the clothes drum is not excessively out of balance during
such high-speed rotation. This may be achieved by making the clothes
drum such that it is self-balancing-- but that reduces the possible size
and hence the capacity of the drum. Alternatively it can be arranged
that whenever the clothes drum is required to rotate at a high spinning
speed this operation is preceded by rotation of the drum at a low
washing speed in the same direction. This solution is not entirely
satisfactory, however, as the speed for washing the clothes must be low
enough to cause the clothes to tumble and not cling to the drum wall,
i.e., the centrifugal force on the clothes must be less than the
gravitational force, and as a result the clothes are not evenly
distributed around the drum wall, as is desired, if the drum is to be in
a balanced condition for the subsequent high-speed spinning operation.

It
is therefore desirable that the drum be rotated at a speed intermediate
the tumbling speed and the spinning speed for a short time prior to
spinning the drum at high speed in order to ensure that the clothes
distribute themselves equally around the internal periphery of the drum
in a balanced manner. This has been achieved, for example, by providing a
drive motor for the drum capable of energization at three speeds, these
speeds being selected by a control arrangement for the machine such
that, on termination of a tumbling action provided by rotation of the
motor at its lowest speed the spin action provided by the motor rotating
at its highest speed is preceded by a short period of rotation at an
intermediate speed where the weight of the clothes is just balanced by
the centrifugal force on the clothes at this speed, the desired result
being that the clothes cease to tumble within the drum and contact the
inner peripheral wall of the drum in a balanced manner. The drive motor
is then accelerated to its highest (spinning) speed. A problem inherent
in this arrangement is that there is no certainty that the clothes will
distribute themselves in a balanced manner in the drum during the period
of rotation at the intermediate speed, as the comparatively rapid
acceleration of the drum from tumbling speed to this intermediate speed
tends to fling the clothes abruptly outwards to the wall of the drum in
the pattern of distribution which they adopt for the previous tumbling
operation (which is very rarely uniform). As a result of this the
acceleration to spinning speed results in large out of balance forces on
the drum.

DC motor including a tubular stator housing having a pair of curved
permanent magnets mounted on the inner surface thereof. A pair of
magnetic pole pieces each comprising a segment of a cylinder are
concentrically mounted in contact with the inner surface of the magnets.
The outer circumference of the pole piece is at least 11/2 times its
inner surface thereby concentrating the magnetic flux and reducing the
stray flux.

1. A direct current
motor comprising a tubular stator housing and a rotatable rotor member
concentrically arranged within said stator housing, first and second
permanent magnets each having the configuration of a hollow tube sector
and concentrically mounted with their outer walls engaging the stator
housing, first and second magnetic pole pieces each comprising a
longitudinal segment of a cylinder having nonradial sidewalls defining
the circumferential limits of the segment so that the outer
circumferential surface of the segment is at least 11/2 times longer
than its inner surface, and means for concentrically mounting said first
and second segments with their outer surfaces in contact with the inner
surfaces of said first and second magnets, respectively, and with their
inner surfaces facing said rotor to define an air gap therewith thereby
to concentrate the magnetic flux within a given area.

2. A motor as claimed in claim 1 wherein each of said
pole pieces are shaped to provide a pair of flat longitudinally
extending surfaces, and said mounting means comprises a pair of
longitudinally mounted rods for each pole piece and bearing against said
flat surfaces.

Description:

The present invention relates to a direct current commutator
motor having a tubular stator and energized by permanent magnets.

Such
motors are frequently used in cases of low power consumption, for
example in toys, in devices for driving electric contacts of automatic
machines, and the like.

However, if higher powers are to be supplied at
larger voltages, such as in domestic apparatus, energization by means of
electromagnets is still preferred because the rotor can then be
magnetized to saturation. The conventional permanent magnets supply a
flux density which is considerably lower than the saturation density of
iron. For example, magnets made of a material which is known under the
trade name of "Ferroxdure" and has been described in British Pat.
Specification 747,724, supplies a flux density of approximately 0.4 Wb/m2, whereas the saturation density of iron is approximately equal to 1.5 Wb/m2.
The same power can then be supplied only if the insufficiently
magnetized rotor is provided with a larger number of turns and has
larger dimensions, which requires a larger quantity of sheet iron.
However, this problem does not play a part in low-power motors so that
in this case there is no objection to using permanent magnets.

The
invention has for an object to provide direct current commutator motors
for higher powers energized by permanent magnets which magnetize the
rotor to saturation. In order to obtain the simplest possible
construction of the stator, the latter should have a tubular from. These
tubes need not be laminated and may be readily cut from long iron
tubes.

A motor, in accordance with the invention, is
characterized in that the permanent magnets are each in the form of a
hollow tube sector, the outer wall of which engages the stator and the
inner wall of which engages a corresponding pole piece along a contact
surface which is larger, and preferably more than 11/2 times larger,
than the surface along which the pole piece adjoins the air gap.

Due
to the apparently extraordinarily large dimensions of the stator when
compared with those of the rotor, however, large permanent magnets can
be used. The emanating flux is indeed proportional to the flux-emanating
surface of the magnet. This flux is then concentrated by means of the
pole pieces and passed on to the rotor. Thus, the pole pieces serve not
only to prevent the occurrence of stray flux but also to provide a
strong flux concentration. The diameter of the rotor may then be chosen
to be smaller for a given power to be supplied. Although the dimensions
of the stator become slightly larger, the cost price of the assembly as a
whole is reduced.

The invention will now be described more fully with reference to the accompanying drawing, in which:

FIG. 2 shows a motor for higher voltages and powers energized by electromagnets.

FIG. 3 shows a motor according to the invention for higher voltages and powers energized by permanent magnets.

FIG. 4 shows one of the permanent magnets used. Each of these FIGS. is a sectional view at right angles to the motor shaft.

The
motor of FIG. 1 is used for low powers and has a tubular stator 1, two
permanent magnets 2 and 3 supplying the energizing flux and a rotor 4.
Such motors are generally supplied with a direct voltage of 6 volts to
12 volts. In domestic apparatus, such as textile-washing machines,
dough-kneading machines, pumps and the like, powers are required which
exceed 100 watts and for which it is desirable to use direct voltages in
excess of 100 volts. For the reasons set out above, the energization is
supplied by one or more windings 5 (FIG. 2) wound onto a pole piece 6
and electrically energized in series or in parallel with the armature
winding or directly by a fixed direct voltage. In this case the pole
piece serves to minimize the reluctance of the magnetic flux circuit and
the stray flux.

The motor according to the invention is shown
in FIG. 3 and is used at the same voltages and for the same purposes as
the motor of FIG. 2. The rotor employed may also the the same. If the
rotor 16 should be used together with a stator in the configuration of
FIG. 1, this rotor would not be saturated and would not be utilized to
its full voltage capacity. Instead of increasing the dimensions of the
rotor or the number of turns, according to the invention, the dimension
of the stator are increased and the configuration of the stator is
altered so that the rotor can nevertheless be magnetized to saturation.

The
increase of the dimensions of the stator 17 permits of also using
larger permanent magnets 7, the flux of which is concentrated through
pole pieces 8 and is passed on to the rotor 16. The ratio of the flux
density at the air gap to the flux density supplied by the magnet 7 is
approximately equal to that of the surface of the inner wall 9 of the
magnet 7 to the surface along which the pole piece adjoins the air gap
10 if the flux is not concentrated too far beyond the knee of
saturation. The desired dimensions of the permanent magnets, the shape
and dimensions of the associated pole pieces and of the stator can thus
be found. Ratios of from 1.5:1 up to 3:1 are suitable.

The outer
wall 18 of each permanent magnet engages the inner side of the stator
17. The stator may consist of soft iron of soft steel and need not be
laminated because the flux variations are small. This also applies to
the pole pieces. However, it is sometimes desirable that the pole pieces
be made of sheet iron because the passing rotor teeth produce a certain
alternating flux. The stator is in the form of a tube. This tube may
have a larger length that the magnet. In this case, the same stator
reluctance can be obtained with a thinner tube. The tube may be closed
at both ends with aluminum discs. The permanent magnets are in the form
of hollow tube sectors (FIG. 4) and may be made, for example, of the
aforesaid "Ferroxdure," of strontium ferrite or of a suitable alloy. The
pole pieces and the magnets may be clamped to the stator, for example,
by means of rods 12 secured in the aluminum discs.

As a matter of course, the invention may also be applied to multipolar motors.

A
direct current commutator motor having a tubular stator housing, on the
inner side of which are arranged curved permanent magnets which are
provided with pole pieces, the surface along which the permanent magnets
adjoin the pole pieces being larger than the magnetically active
surface between the pole pieces and the rotor.

IGNIS K12 (PHILIPS) AWF627/IG P.M. SYSTEM DRIVING ARRANGEMENT FOR THE DRUM OF A WASHING MACHINE:

1. In an automatic washing machine including a commutating electric
motor for driving the drum of the washing machine at a first
comparatively low-washing speed and at a second comparatively
high-spin-drying speed, the improvement comprising an automatic speed
adjusting circuit for said motor comprising, a pair of input terminals
adapted for connection to an AC voltage supply source, a supply circuit
for the motor connected to the input terminals and provided with at
least two further terminals, an electric heating element arranged to
heat the wash water and connected across said two further terminals, a
controlled rectifier connected in the supply circuit so as to regulate
the motor speed at a given washing speed, and means connecting said two
further terminals in the motor supply circuit so that the motor is at
least substantially energized through at least a part of the heating
element whereby it exhibits a speed characteristic which decreases very
sharply with increasing load.

1. In an automatic
washing machine including a commutating electric motor for driving the
drum of the washing machine at a first comparatively low-washing speed
and at a second comparatively high-spin-drying speed, the improvement
comprising an automatic speed adjusting circuit for said motor
comprising, a pair of input terminals adapted for connection to an AC
voltage supply source, a supply circuit for the motor connected to the
input terminals and provided with at least two further terminals, an
electric heating element arranged to heat the wash water and connected
across said two further terminals, a controlled rectifier connected in
the supply circuit so as to regulate the motor speed at a given washing
speed, and means connecting said two further terminals in the motor
supply circuit so that the motor is at least substantially energized
through at least a part of the heating element whereby it exhibits a
speed characteristic which decreases very sharply with increasing load.

2. A washing machine as claimed in claim 1 further
comprising a switch by which the further terminals can be directly
connected to the input terminals in the cutoff condition of the motor,
and means connecting the switch across the series combination of the
motor and the controlled rectifier.

3. A washing machine as claimed in claim 2 wherein the
supply circuit includes a full wave bridge rectifier, means connecting
one of the further terminals to one of the input terminals and another
one of the further terminals to one of the input terminals of the bridge
rectifier, and means connecting the switch between the two input
terminals of the bridge rectifier.

4. A washing machine as claimed in claim 1 further
comprising a braking switch by which the motor can be connected across
the heating element when the motor supply circuit is interrupted.

5. A washing machine as claimed in claim 1 further
comprising means for varying the mechanical load on the motor during a
given washing cycle.

6. An automatic speed control circuit for an electric
motor subject to a wide variation in load during a normal cycle of
operation comprising, a source of supply voltage, said motor having a
given speed torque characteristic if connected to said supply voltage
such that it exhibits a given speed variation between the expected
minimum and maximum values of load, means for varying the load on the
motor between said minimum and maximum load values during a normal cycle
of operation of the motor, a controlled rectifier connected in series
with the motor, means for adjusting the firing angle of said controlled
rectifier as a function of motor speed so as to regulate the motor speed
at one of said load values, a resistor, and means connecting at least a
part of said resistor in series with the motor across said voltage
source so that the speed characteristic of the motor is changed to
substantially increase said given speed variation between said expected
minimum and maximum values of load.

7. A control circuit as claimed in claim 6 for use in an
automatic washing machine and further comprising a programming device
controlling said load varying means and the wash cycle, means controlled
by said programming device for periodically deactivating the motor
during a wash cycle, and switching means controlled by the programming
device for selectively connecting said resistor directly across the
voltage source during the time the motor is deactivated during a wash
cycle.

8. A control circuit as claimed in claim 7 wherein said
resistor is a heating element located so as to heat the wash water, said
circuit further comprising a braking switch for selectively connecting
the heating element across the motor in the event that the motor supply
circuit is opened.

Description:

This invention relates to an arrangement including a commutating
electric motor for driving the drum of a washing machine provided with
at least one electric heating element, especially an automatic washing
machine having at least one comparatively low-washing speed and also at
least one comparatively high-spin-drying speed, which arrangement has a
pair of input terminals for connection to a source of supply voltage and
a supply circuit for the motor connected to these terminals.

Such
arrangements are known and are at present used in most automatic
washing machines. At least two widely different speeds (ratios of the
order of 1:20 or more are commonly used) are obtained in various
manners, for example, by means of two different motors, by means of a
kind of gearbox having at least two speeds, by the use of two or more
belt or cord drives with different ratios or by a transformer provided
with tappings enabling a single motor to be energized with different
voltages.

It is an object of the invention to provide a
simplified, particularly lightweight and cheap and yet reliable
arrangement of the aforementioned kind. The invention is based on the
experience that when a self-commutating electric motor is energized
through a resistor of sufficient value its load can be increased to an
extent such that, it runs regularly at an unexpectedly low speed without
exceeding the permissible motor current. In other words, the motor
acquires a kind of highly exaggerated series characteristic. The
invention is also based on the recognition that just this characteristic
is very useful in a washing machine because, during the washing
operation, when the tub is full of water which must be kept hot or be
heated, the motor is heavily loaded and will consequently run at a low
speed and consume much current. As a result, the energy dissipated in a
series resistor will be large and may be utilized for heating or keeping
the water hot, whereas during the spin-drying operation, when the water
has been discharged from the tub, the motor is only lightly loaded and
will reach a high speed while consuming little current so that the
energy dissipated in a series resistance will be comparatively small and
can readily be removed, even without water cooling.

The
arrangement in accordance with the invention is characterized in that it
is provided, in addition to the aforementioned input terminals, with at
least two further terminals for the connection of a heating element of
the washing machine. The latter terminals are included in the motor
supply circuit so that the motor is at least substantially energized
through at least part of this heating element, whereby it exhibits a
speed characteristic which very strongly decreases with increasing load.

It should be noted that it is known from the U.S. Pat. No.
1,998,670 to feed an electric motor through a heating element. This
patent is however concerned with a fan motor which serves to maintain
the air circulation about a heating element of an electric stove in
order to provide a better distribution of heated air by forced
convection. Consequently, this motor operates with a substantially
constant small load and always runs at a normal, comparatively high
speed, so that it does not make use of an exaggerated series
characteristic and/or of the aforementioned related useful effects
occurring in a washing machine.

The invention may be used with
any kind of commutating motor: with commutator motors provided with
series shunt or compound energization or energization by a permanent
magnet fed with smoothed or unsmoothed direct current or with
alternating current, or with motors having a rotating permanent magnet,
for example, with commutatorless motors provided with an electronic
commutator, for example, motors using Hall plates as control elements.

During
a washing cycle the load on the motor varies with the amount of washing
goods with which the drum of the washing machine is filled and/or with
the level of the water in the tub of the machine, whereas the washing
effect is an optimum at a given speed of revolution. Therefore the
arrangement preferably includes a known control device by which the
motor speed is regulated at at least one washing speed. In an
arrangement for connection to an alternating voltage supply source, this
control device may, for example, include a controlled rectifier by
which the motor speed is regulated.

Features and advantages of
the invention will appear from the following description of embodiments
thereof, given by way of example only, with reference to the
accompanying drawings, in which:

FIG. 1 is a circuit diagram
showing the basic elements of a simple embodiment of an arrangement in
accordance with the invention,

FIG. 2 shows the speed vs. torque
characteristic of the motor of the arrangement shown in FIG. 1 compared
with the characteristic of a conventional series-energized commutator
motor.

FIG. 3 is a circuit diagram showing the basic elements of
an automatic washing machine equipped with a second embodiment of the
arrangement in accordance with the invention,

FIG. 4 is a circuit diagram of a third embodiment, and

FIG. 5 is a circuit diagram of a fourth embodiment of the arrangement in accordance with the invention.

In
the simplest possible embodiment shown in FIG. 1, the arrangement
according to the invention comprises a commutating electric motor 1, for
example, a motor with permanent-magnet energization. It further
comprises a pair of input terminals 2, 2' for connection to a voltage
supply source and a supply circuit 3, 3', 4 for the motor 1 connected to
the said terminals. According to the invention the arrangement is
provided with two further terminals 5 and 6 for the connection of a
heating element 7 of the washing machine. These terminals 5, 6 are
included between the parts 3 and 3' of the motor supply circuit 3, 3', 4
so that the motor 1 is energized through the heating element 7.

In
a practical embodiment the motor 1 was a motor provided with
permanent-magnet energization rated for a DC supply voltage of 220
volts, with a maximum current of 6.4 amperes at a heavy load and
designed for driving the drum of a washing machine at a spin-drying
speed of 800 revolutions per minute. The heating element 7 had a
resistance value of 32 ohms and was proportioned to be likewise
connected to a 220 volts supply voltage in the case of water cooling.

Line
A of FIG. 2 shows the speed-torque characteristic (speed n as a
function of the load torque K) of the motor 1 of the arrangement shown
in FIG. 1 when supplied with a direct voltage of 220 volts through the
heating element 7 having a resistance value of 32 ohms.

Curve B
of FIG. 2 shows, by way of comparison, the characteristic of a
conventional series-energized commutator motor supplied directly with a
direct voltage of 220 volts.

At a small load, which corresponds
to the spin-drying operation, the motor 1 runs at a speed of 800
revolutions per minute and this speed can increase only by a small
amount (to about 900 revolutions per minute) at a theoretical zero load
torque. Under a heavy load (k=8, which corresponds to a current of 6.4
amperes) this motor runs at a constant speed of only 50 revolutions per
minute. The attained speed ratio is thus 16 to 1.

By way of
comparison the curve B of FIG. 2 shows that with a conventional
series-energized commutator motor directly fed with its rated voltage,
the ratio between normal speed at a small load, which corresponds to the
spin-drying operation (K=1), and the speed at the maximum permissible
load (K=8) is not even 2 to 1.

In a washing machine the characteristic A provides many important advantages:

a.
changing from a low-washing speed to a high-spin-drying speed or vice
versa can be automatically effected by decreasing or increasing the load
by draining or filling the tub with water.

b. The peak starting current of the motor is limited by the resistance of the heating element.

c.
Acceleration to the spin-drying speed is very gradual, especially if
the motor is started before the tub has been completely drained.
Consequently, the mechanical starting shock is heavily damped or even
entirely suppressed while the articles to be washed are distributed
about the drum in an optimum manner since the speed increases slowly
during the draining of the tub.

d. The resistance of the heating
element prevents the motor from reaching an excessive spin-drying
speed, for example, in the case of an abnormally high-supply voltage,
and protects the arrangement in the case of a short circuit of the motor
and/or of its supply circuit and/or if the drum locks.

e. The
energy dissipated in the heating element is largest during the washing
operation when the water in the tub must be heated or kept hot, but
during the spin-drying operation it is so small that it can readily be
carried away by the air then contained in the tub without inconvenience
for the element, the machine and/or the articles being washed.

f.
Finally, when the supply circuit of the motor is interrupted, the motor
can rapidly be brought to a standstill by short circuiting it through
the heating element so that much more costly protection devices can be
economized.

The automatic washing machine the basic circuit
diagram of which is shown in FIG. 3 includes a second embodiment of the
arrangement in accordance with the invention. In this embodiment the
motor supply circuit includes a first changeover switch 8, for example,
in the form of a relay changeover contact, by means of which the heating
element can be directly connected across an alternating-voltage supply
2, 2' to speed up the heating of the water contained in the tub of the
machine. This supply circuit includes, in series with the switch 8, a
double-pole changeover switch 10, 10', for example, likewise in the form
of relay changeover contacts capable of reversing the direction of the
current flowing through the motor 1 and hence the direction of rotation
of this motor, and a controlled semiconductor rectifier or thyristor 9
by means of which, at at least one washing speed, the motor speed is
regulated by simple controlled rectification of the current flowing
through the heating element 7 and the motor 1.

Apart from the
above-described arrangement the automatic washing machine includes a
motor governor 11 by which the thyristor 9 is controlled during the
washing operation so that the motor 1 drives the drum of the machine at a
substantially constant speed of, say, 50 revolutions per minute. The
machine further includes a reversing circuit 12 which controls the
switches 8 and 10, 10' so that, during the washing operation the motor 1
alternately and with time intervals rotates in one direction and then
in the other direction whereby, during the heating and during the time
intervals, the switch 8 can be brought into its lower position so that,
if required, a larger electric power is dissipated in the heating
element.

The automatic washing machine is provided with a second
motor 13 which drives a water pump capable of draining the machine tub.
This motor is controlled by a switch 14, for example, a relay contact,
which is in turn controlled by a programming device.

The
programming device, which also is shown diagrammatically only, comprises
a cycle counter 16 by which three electronic switching devices are
operated in the correct sequence:

a filling device 17 by which
two water supply valves 18 and 19 are opened in a predetermined order
and are closed again when the water in the tub reaches a level
determined by a detector 20;
a heater 21 by which the thyristor
is cut off when the temperature of the water in the tub measured by a
transducer 22, for example, a NTC resistor, reaches a predetermined
value, for example, 90° C.;

a pump control device 23, which is controlled by a second water level detector 24.

The cycle of operations of the reversing circuit 12 is also controlled by the cycle counter 16.

The
automatic washing machine is provided with a switch 25 which is
rendered operative by the pump control device 23 and switches off the
machine when the water level measured by the second level detector 24
becomes zero during the spin-drying operation. Finally, the system
includes a safety switch 26.

The automatic washing machine described can carry out, for example, the following program:

After
switching on, the first program cycle (preliminary washing) commences:
the tub is first filled with water, with the addition of a washing agent
as the case may be, through the first valve 18.

At the instant
at which the correct water level is reached, the motor 1 is started
through the cycle counter 16 and under the control of the heater 21 and
the transducer 22. The operating cycle of the reversing circuit 12 is
such that the motor runs alternately in both directions for periods of
12 seconds with time intervals of 3 seconds. The temperature rises
slowly because the heating element 7 is directly connected to the input
terminals during the short time intervals only, during which it
dissipates a power of, say 3 kilowatts, whereas with a running motor its
dissipation is restricted to, say, 1 kilowatt. When the temperature of
the water reaches a value of, say, 30° C. the motor 13 is switched on
through the counter 16 by the switch 14 and under the control of the
device 23 and the second level detector 24 which switches it out again
as soon as the tub is empty, whereby the motor 1 can be switched out if
desired, for example, by 21, 22, but this is not necessary.

The
second program cycle (washing) proceeds similarly to the first, with the
difference that the tub is now filled through the second valve 19, with
washing agent added, and that the cycle of operations of the reversing
circuit is changed through cycle counter 16, for example, to running for
periods of 3 seconds in alternate directions with time intervals
in-between of 12 seconds, and that a different temperature limit of,
say, 90° C. can be chosen for this program cycle.

The third
program cycle (rinsing) proceeds similarly to the first, with the sole
difference that the tub is filled again through the second valve 19, but
without the addition of washing agent.

The next few (for
example, three) program cycles (rinsing) proceed similarly to the third
but without heating during the intervals and without the use of the
temperature limit, the step controlled by elements 21, 22 being skipped.

The last program cycle (spin-drying) consists in that the motor
governor 11 switches to the spin-drying speed before the tub is fully
drained by the motor 13. In this process the reversing circuit 12 is
rendered inoperative by the cycle counter 16 and a power of only about
150 watts is dissipated in the heating element 7.

When the
supply of water to the tub from the drum and from the washing goods
ceases, the machine is switched off by the switch 25 and all its
components return to their respective rest positions, in which they
remain until the machine is started again. If the machine is
inadvertently opened during operation, the door or cover automatically
switches the safety switch 26 from the operative position shown to the
other position in which it interrupts the lead 4 of the supply circuit
and short circuits the motor 1 through the heating element 7, the switch
8 and the reversing switch 10, 10' so that the motor is vigorously
braked by this circuit and is brought to a standstill within a very
short time (of the order of 3 seconds) even from the highest spin-drying
speed.

It should be noted that the motor can also be stopped by
cutting off the thyristor 9, in which case no electric power is
supplied to the heating element 7 during the intervals. It will have
attracted notice that the described automatic washing machine does not
include any of the otherwise commonly used time-measuring devices. The
cycle counter 16 is simply switched from one cycle to the next under the
control of the transducers 20, 22 and 24, and the time-measuring device
is replaced by an accurate temperature transducer 22. This provides
equally satisfactory or even better washing results than with the use of
a more expensive time-measuring device.

FIG. 4 shows a third
embodiment of the arrangement in accordance with the invention. This
embodiment mainly differs from that shown in FIG. 3 by the inclusion of a
full-wave rectifying bridge circuit 30 between the input terminals 2,
2' and the motor supply circuit 3, 3', 4 provided with the further
terminals 5 and 6, between which the heating element 7 is shown.
Furthermore, the changeover switch 8 of FIG. 3 is replaced by a
short-circuiting switch 8', and a flywheel diode 31 is connected across
the motor 1 and the reversing switch 10, 10'.

By the use of the
supply rectifier 30 the power supplied to the motor and to the heating
element 7 through the thyristor during each half cycle of the AC supply
voltage is about doubled so that the motor 1 can produce a higher
torque, even with increased dissipation in the heating element 7.

The
flywheel diode 31 ensures that the thyristor 9 is extinguished between
successive half cycles of the AC supply voltage and of the rectified
voltage across the output terminals of the full-wave rectifier 30. It
may also contribute somewhat to the improvement of the control
properties and of the form factor of the arrangement, at least at
certain speeds. An embodiment of the motor governor similar to the motor
governor 11 of FIG. 3 is shown in detail in FIG. 4. The motor 1 is
switched off by means of a switch 32, by which the control electrode of
the thyristor 9 can be directly connected to its cathode so that the
thyristor can no longer be fired. If electric energy is to be dissipated
in the heating element 7 with the motor stationary, the switch 8' can
be switched on.

The control electrode of the thyristor is also
connected to its anode through a resistor 33 of, say, 4.7 kΩin series
with three Zener diodes 34 having an overall Zener voltage of, say 225
volts and with a diode 35 connected in the forward direction. A control
circuit is connected to the junction point of the diode 35 and the Zener
diodes 34. This comprises a second diode 36 connected in the forward
direction and two further Zener diodes 37 each having a Zener voltage of
7.5 volts. A control switch 38 is connected to the negative lead 4 of
the motor supply circuit. This switch has four positions. In its first
position a it connects the end of the control circuit 36, 37 remote from
the diode 35 to the lead 4. The firing of the thyristor 9 through the
circuit 33, 34, 35 is then delayed by the control circuit 36, 37, so
that the motor 1 runs at a controlled normal washing speed of 50
revolutions per minute stabilized by the counteraction of its back
E.M.F. in the cathode circuit of the thyristor 9.

In its second
position b the switch 38 connects the junction point of the two Zener
diodes 37 to the lead 4 so that the firing of the thyristor 9 is even
more delayed by the circuit 36, 37. The back E.M.F. of the motor 1 is
compared now to the forward voltage across only one of the Zener diodes
37. Accordingly the motor 1 runs at a stabilized, particularly
low-washing speed of only 25 revolutions per minute.

In its
third position c the switch 38 connects the cathode of the diode 36 to
the lead 4 through a resistor 39 of, say, 4.7 kΩ, the Zener diode being
short circuited by a switch 40 which is coupled to the switch 38. The
back E.M.F. of the motor 1 is then compared to the voltage drop across
the resistor 39. If this back E.M.F. is equal to zero (for example at
starting), the thyristor 9 becomes conductive as soon as its anode
voltage exceeds the sum of the voltage drop across the resistor 33, the
threshold voltage of the diode 35 and the threshold voltage of the path
between its control electrode and its cathode. The resistor 39 is chosen
such that the motor 1 is accelerated to a reduced spin-drying speed of
350 revolutions per minute and continues running at this stabilized
speed.

In the positions a and b of a practical embodiment of the
arrangement the variations of the motor speed due to load variations
(between K=1 and K=8 in FIG. 2) and to variations of the AC supply
voltage of ± 10 percent were between -4 and +6 percent, and the speed
variations due to variations of the ambient temperature between 26° and
61° C. were between -0.6 percent and +2.1 percent.

In its fourth
position d the control switch 38 is open and renders the control
circuit 36, 37 inoperative while the Zener diodes 34 are short circuited
by the switch 40. The thyristor 9 begins to conduct as soon as its
anode voltage minus the back E.M.F. of the motor 1 exceeds the sum of
the threshold voltages of the diode 35 and of the control
electrode-cathode path of the thyristor. The motor 1 is supplied with
substantially complete half cycles of the AC supply voltage and is
accelerated at an even higher rate than in the third position of the
control switch 38. It reaches a spin-drying speed of 725 revolutions per
minute and continues running at this speed.

FIG. 5 is a circuit
diagram of a fourth embodiment. In this embodiment the rectifying
bridge 30 of FIG. 4 is replaced by a rectifying bridge 30' the output
terminals of which are directly connected to the input terminals of the
reversing switch 10, 10'. The bridge input terminals are connected to
the input terminal 2' of the device through the lead 4 of the motor
supply circuit and to the further terminal 6 through the lead 3' of the
same supply circuit, respectively. In addition, the switch 8' of FIG. 4
is replaced by a changeover switch 8" connected between the input
terminals of the rectifier bridge 30'. This provides the advantage that
the rectifier 30' need not supply the high-heating power to the heating
element 7 when this element is connected to the full supply voltage
through the switch 8". Consequently, the heating element 7 is always fed
with alternating current.

The arrangement includes a third
further terminal 6' to which a tapping of the heating element 7 is to be
connected and which can alternatively be connected to the further
terminal 5 in the absence of such a tapping. The motor governor 11 of
FIG. 3 or 33-40 of FIG. 4 is here replaced by a two-position governor
provided with a switch 11' by which either part or the whole of the
heating element 7 can be short circuited when the rectifier 30' is not
short circuited. This switch can, for example, be a normally open
contact of a relay energized by an adjustable portion of the back E.M.F.
of the motor 1 or of the voltage delivered by a tachogenerator (NOT IN PM SYSTEM) .

IGNIS K12 (PHILIPS) AWF627/IG P.M. SYSTEM METHOD OF SWITCHING A DIRECT-CURRENT MOTOR OF A WASHING MACHINE:

A circuit arrangement for a direct-current motor for a washing machine,
which motor is equipped with permanent magnets for starting the spinning
operation from a predetermined direction of rotation of the oscillatory
washing movement for the washing operation, irrespective of any manual
operation of the timer. The operation of the timer and of the voltage
change-over device of the motor are effected independently of one
another by means of one or two motors. The arrangement may be used in
washing machines equipped with direct-current motors which permit of
starting the spinning operation either with the tub filled or with the
tub empty.

1. A washing machine comprising, a direct-current motor for
driving a drum of the washing machine at a low washing speed in two
directions of rotation and at a high spin-drying speed in one direction
of rotation, a timer for controlling the sequence and the time duration
of the various washing machine operations, a reversing switch which
includes first switching means for selectively controlling the electric
supply for the motor so as to provide switching to the low washing speed
and two directions of rotation and for switching to the high spinning
speed, said timer controlling second switching means which control the
motor electric supply and the energization of the reversing switch and
which short-circuit said first switching means having the same functions
but appertaining to the reversing switch, means driven by the timer for
initially rendering said second switching means inoperative when
switching the machine from a low speed wash cycle to a high speed spin
cycle, whereupon the part of said first switching means appertaining to
the reversing switch are rendered inoperative at an instant determined
by the

2. A washing machine as claimed in claim 1,
characterized in that the timer and the reversing switch are
independently driven by appropriate means.

3. A washing machine as claimed in claim 2,
characterized in that the timer and the reversing switch are driven by
at least one alternating current

4. A washing machine control system comprising, a
reversible DC motor for driving the washing machine drum at a low
reversible wash speed and at a high spin-drying speed in one
predetermined direction of rotation, reversing switch means that
includes first, second and third switching means coupled to the motor
terminals, to the motor electric supply, and to a control winding for
controlling the reversing switch means, respectively, said first
switching means controlling the direction of motor rotation, said second
switching means controlling the motor speed and said third switching
means controlling said control winding, a timer for controlling the
sequence of washer operations and the time duration thereof and
including fourth and fifth switching means connected in parallel with
said second and third switching means, respectively, said timer being
operative to open said fourth and fifth switching means prior to the
start of a spin-drying cycle so that said second and third switching
means assume control of the motor speed and the reversing switch,
respectively, said second and third switching means then being operated
in a predetermined relation to the operation of said first switching
means to a condition to provide said predetermined direction of motor
rotation whereby said second switching means adjusts the electric supply
to provide said high spin-drying speed and said third switching

5. A control system as claimed in claim 4 further
comprising a pair of input terminals connected to a source of AC supply
voltage, rectifier means coupling said AC supply terminals to the motor
via said first switching means to provide a reversible DC voltage to the
motor, and means connecting said parallel connected third and fifth
switching means in

6. A control system as claimed in claim 5 wherein said
timer is arranged to close said fourth and fifth switching means during a
wash cycle thereby to operate the motor alternately in both directions
of rotation and at said low washing speed.

Description:

This invention relates to a device for switching a
direct-current motor intended for driving a drum of a washing machine at
a low washing speed in two directions of rotation and at a high
spin-drying speed in one direction of rotation. In this device use is
made of a timer which determines the sequence and the durations of the
various operations, while a reversing switch is provided which includes
switching means for the electric supply of the motor, both for switching
to the low washing speed in two directions of rotation and for
switching to the high spin-drying speed.

In known washing
machines the oscillatory rotation movement of the wash-drum is obtained
by reversing the direction of rotation of the motor of the machine. It
is also known for a washing machine to be driven by a change-pole
alternating-current motor in which, by changing over the poles, two
speeds are obtainable, the washing speed and the spin-drying speed, the
latter being considerably higher than the former. The reversal of the
direction of rotation of the motor at the washing speed is achieved by
means of a reversing switch included in the control unit of the machine.
In automatic or semi-automatic washing machines this control unit
ensures the sequence and the duration of the operations to be performed
according to a selected program, such as washing, heating, rinsing and
spin-drying. In such a cycle, switching from washing to spin-drying is
to be effected when the reversing switch is out of the circuit.
Frequently this will give rise to locking of the drum because the
reversing switch is rendered inoperative before the change-over to the
spin-drying speed has been effected.

The commonly used control
units comprise a timer which determines the sequence and the duration of
the operations and a reversing switch. The timer and the reversing
switch are mechanically coupled together and are driven by a single
motor. This embodiment permits a saving both in the space occupied and
in material used.

In the so-called "thermostatic" machines, the
timer is stopped during the heating period, i.e. during the time in
which the wash-water has not yet reached the desired temperature.
However, during this time, the wash-water must continue to be agitated
and hence the wash drum has to perform its oscillatory movement.
Consequently, during the stationary period of the program, another
driving device is required to rotate the cams which control the
reversing contacts until the desired water temperature has been reached.
In the timers available so far, either a device which disengages the
program part or a two-speed motor is used. The part of the timer which
controls the reversal of the movement generally comprises a limited
number of switches since the reversal of the direction of rotation in
alternating current motors requires only single-pole commutation.

In
washing machines equipped with direct-current motors, the motor can be
made to run not only in two directions but also at different speeds by
merely controlling the electric supply. Although this a highly
interesting property, realization gives rise to great switching and
safety problems. This problem may be explained with reference to FIGS. 1
and 2 of the accompanying diagrammatic drawings.

The invention will now be described in greater detail with reference to the accompanying drawing, in which:

FIG. 2 schematically shows a modified form of the arrangement of FIG. 1,

FIG. 3 shows a preferred form of the invention, and

FIG. 4 illustrates the cyclical operation of the various switches of the arrangement of FIG. 3.

Double-pole
switching of a direct-current motor is shown schematically in FIG. 1.
In order to reverse the direction of rotation of the motor, the polarity
of the voltage at the motor terminals is reversed by closing either the
switches 1 and 3 or 2 and 4.

For example, to bring the wash
drum from the washing speed (say 50 rev/min) to the spin-drying speed
(from 500 to 1,000 rev/min.) it is sufficient to change the supply
current at the motor terminals and to render the reversing arrangement
inoperative. If the timer is equipped with a single motor, the reversing
switches will rotate continuously. Hence the reversing arrangement must
be rendered inoperative, resulting in a circuit diagram as shown in
FIG. 2. In this circuit arrangement the program part comprises two
switches 15 and 16 which are present to enable the supply circuit,
including the reversing switches, to be interrupted, and two switches 17
and 18 which must be closed to feed the motor so as to obtain the
required spin-drying speed and the proper direction of rotation, which
must be maintained during the entire spin-drying period. The switches
15, 16, 17 and 18 are controlled by the timer. However, they may lead to
an uncontrolled speed when the timer button is manually operated, and
they also may cause the wrong polarity to be switched into circuit when
the polarity has not yet been reversed. The broken lines of FIG. 2 show
the paths which the current takes when the switches are too quickly
operated.

Before the spinning period begins the switches 15 and
16 are closed and the motor is fed through switches 12 and 14. The
negative polarity then occurs at 14 and the positive polarity at 12,
which is also the case at one of the contacts of the switches 17 and 18.
When the latter switches are closed, a double short-circuit occurs,
namely in the circuit including the elements 17, 15 and 14 (the switch
17 closes, the switch 15 has not yet been opened and the switch 14 is in
the closed position) and also in the circuit including the elements 12,
16 and 18 (the switch 18 closes, the switch 16 has not yet been opened
and the switch 12 is in the closed position).

Since the electric
supply for the direct-current motor is taken from the
alternating-current lines through a rectifier bridge comprising
semiconductor elements, the latter will act as fuses and the supply
arrangement of the motor will be badly damaged.

The problem of
changing the speed and reversing the direction of rotation of a
direct-current motor by means of a timer in which the functions
"sequence and duration" and "reversal" are combined would appear to be
insoluble when very fast operation of the reversing switches by manual
turning of the times button is possible.

It is an object of the
present invention to avoid this disadvantage and to make the switching
of the sequence and duration independent of the reversal. The invention
is characterized in that in switching from the washing speed to the
spinning speed, initially switching means, which appertain to the timer
and control the motor supply and the drive of the reversing switch, and
which short-circuit switching means having the same functions but
appertaining to the reversing switch, are rendered inoperative by means
driven by the timer, whereupon the said switching means appertaining to
the reversing switch are rendered inoperative at an instant which is
determined by the reversal of the direction of movement of the
wash-drum. The arrangement according to the invention ensures that the
spinning operation is started under predetermined conditions, and that
the direct current is switched by means of a reliable device operating
with a high degree of safety, irrespective of any manual operations.

British
Pat. specification No. 244,026 describes a washing machine including a
control arrangement for reversing the direction of rotation of the motor
independently of the program arrangement which determines the duration
of the various stages of the washing cycle and also the supply of water
and the washing ingredients. Each of these arrangements includes a drum
provided with segments which is driven by a motor and travels past
carbon brushes which control the various operations. The safety of the
circuits upon reversal of the direction of rotation of the motor is
ensured by switching into circuit electric starting resistances by means
of the drum switch which determines the reversal of the movement. The
reason for separating the operation of the timer and of the reversing
switch is to permit the wash drum to be stopped with its door
registering with the door of the machine. No provision is made for a
spin-drying operation and hence for variation of the motor supply
voltage.

In an embodiment of the present invention, the washing
machine includes a direct-current motor equipped with permanent magnets.
The motor is fed from the alternating current supply through a known
supply arrangement providing current rectified by semiconductor
elements. The automatic coordination arrangements which are used for
performing the reversing and timer functions and which usually are
controlled by a single alternating-current motor are separated so as to
be independent of one another, the reversing arrangement and the timer
arrangement each being operated by a separate motor. The use of
alternating-current motors for these automatic coordination devices
provides the advantages of simple design and at the same time of a
particularly constant speed, e.g., by using a synchronous motor.

The
method and the arrangement according to the invention will now be
described more fully with reference to a circuit diagram shown, by way
of example, in FIG. 3. The switches represented by two parallel lines
form part of the reversing arrangement and those represented by a single
line form part of the timer. The reversing switches 21 and 23 relate to
a first direction of rotation during the washing operation and to the
preferential direction of rotation during spin-drying, and the switches
22 and 24 relate to the second direction of rotation during the washing
operation.

Furthermore, it is assumed that spinning is started while the tub still is filled with water.

It
is desirable to have a preferential direction of rotation for the
spinning in view of certain constructional details of the machines, one
such detail being that the location of the draining system of the
machine permits it to be emptied faster when the drum rotates in a
predetermined direction.

Starting of the spinning in a
preferential sense is a known problem, the solution of which will be
different for different electrical arrangements used.

The
reversing switch 25 controls the AC supply of a motor M. When this
switch 25 is closed, the characteristics of the current supplied to the
motor correspond to the washing speed. When the switch 25 is open, these
characteristics correspond to the spinning speed. The switch is opened
in an accurately determined condition of the reversing arrangement (for
example, when the switches 21 and 23 are closed).

In order to
maintain a given direction of rotation during spinning, the motor of the
reversing arrangement is stopped by opening the switch 26. The switch
27, which controls the pump for draining the tub, is closed when the
motor of the reversing arrangement is stopped. This switch 27 may
alternatively be operated by the timer part when spinning is started
with the tub empty.

The switches 25', 26' and 27' are the timer switches which provide for normal operation when spinning is not required.

The machine operates as follows:

Washing:
the switches 25, 26 and 27 are short-circuited by switches 25', 26' and
27' which are controlled by the timer with the reversing arrangement
rotating; the direct-current motor operates in a predetermined rhythm in
two directions of rotation.

Spinning: the start of a spin cycle
is effected in two stages. First the timer orders the timer switches
25', 26' and 27' to be opened. The switch 26 of the reversing motor
remains closed, and the voltage corresponding to the washing speed
continues to be applied to the direct-current motor, while the reversing
motor continues to rotate.

At a given instant of the reversing
cycle (when the switches 21 and 23 are closed) the switch 25 is opened
(see FIG. 4) so that the spinning operation may start and then the
switch 26 is opened so that the reversing motor is stopped. Opening the
switch 25 ensures the start of the spinning operation. As soon as the
reversing motor stops (in response to the open condition of switch 26),
all of the reversing switch contacts remain in the positions shown in
FIG. 4 with switches 25 and 26 open, switch 27 closed, switches 21 and
23 closed and switches 22 and 24 opened. The spin cycle continues until
the timer orders a new set of conditions by operating the timer switches
25', 26', and 27'.

FIG. 4 shows the reversing cycle and the
positions of the various switches of the reversing arrangement during
this cycle, i.e., the program of the reversing switch and the condition
of its various contacts, open or closed, brought about by the reversing
switch cam discs during their rotation. The opening and closing of these
contacts have no effect as long as the corresponding timer contacts
such as 25' and 26' remain closed.

Contacts 25' and 26' open
only if the timer orders a spin cycle and then the reversing switch
alone takes over briefly to insure that the spin cycle will begin only
if contacts 21 and 23 are closed and 25 is open. Switch 26 then opens
shortly thereafter to stop the reversing switch motor whereupon the
various reversing switch contacts are held in position until the timer
takes over control of the remaining operations in the washer program
cycle via the timer switches such as 25', 26' etc..

The
reversing arrangement is of conventional design: a shaft which is
integral with a motor (1 rev/min) carries cams the protuberances of
which operate either directly or through levers upon a contact element.
The protuberances which effect the closure of the switches 21 and 22 are
arranged at diametrically opposed points on the same cam, a second cam
carrying the protuberances which operate the switches 23 and 24. The
protuberances which operate the switches 21 and 23 are rigidly disposed
opposite one another. The contact period, i.e., the time of rotation in
the same direction is 12 seconds and is followed by a stationary period
of 3 seconds. The cams which ensure switching on of washing and spinning
operations (switch 25) and stopping of the reversing motor (switch 26)
ensure a permanent contact during the entire time of rotation except for
a short interval during which the switch 25 is open to enable the
application of the spinning voltage while, only fractions of a second
later, the switch 26 is opened, which enables the reversing arrangement
to be stopped. The recesses of these cams are rigidly arranged in the
center positions of these protuberances for the switches 21 and 23 which
provide the preferential direction of rotation. The interval between
the instants at which the switches 25 and 26 are opened enable the
reversing motor to be stopped as soon as the spinning speed has been
switched on.
The cam which carries the protuberance for
operating the switch 27 is located opposite the recess of the cam
operating the switch 25 and ensures the starting of the draining pump
and also the starting of the spinning operation.

The switch 27'
is provided only if it is desired to drain the tub on termination of a
washing operation without subsequent spin-drying or if draining of the
tub is to commence before spinning is started.

The advantages of this method of starting from the washing speed to the spinning speed are many.

The
starting of the spin-drying operation is tied only to the reversing
arrangement. Manual operation of the timer does not influence the manner
of switching of the spinning operation (since the operation of the
reversing arrangement is separate from that of the timer).

In
this manner the problem of switching for reversal is simplified as far
as possible since the system uses a smaller number of contacts than the
circuit arrangement of FIG. 2, and moreover, complete safety is
obtained, preventing a short-circuit.

In a conventional
reversing arrangement it would not be possible to obtain intervals of
precise duration as short as one second, for the diameter of the cams is
comparatively small (about 15 mm). In the reversing arrangement
according to the invention, however, this diameter is about 60 mm, while
the motor speed is 1 rev/min, so that a second corresponds to about 3
mm of the circumference. Thus, if short-duration intervals are desired, a
cam having a diameter of this order may be notched with a sufficient
degree of accuracy.

In another embodiment of a washing machine
operating in the aforedescribed manner, the timer and the reversing
arrangement are independently driven by a single motor by means of a
known appropriate gearing which may be mechanical, electromagnetic,
electronic or hydraulic.

Such a switching method may be used in
washing machines equipped with a direct-current motor which may be
switched to spinning speed either when the tub is filled or when it is
empty.

IGNIS K12 (PHILIPS) AWF627/IG P.M. SYSTEM Device for controlling the spin-drying speed in a washing machine:

Device for controlling the spin-drying speed in a washing machine having
a d.c. motor. During spin-drying, the motor speed is limited by a
resistor in a control circuit. During acceleration of the motor to
spin-drying speed, the speed is limited to a minimum spin-drying speed
by a water level sensing switch contact connected to the resistor.

1. In a washing
machine of the type comprising a tub, a drum mounted for rotation within
the tub, a d.c. motor for driving the drum at least at a low washing
and a high spin-drying speed, a water level control device, switching
means for changing from washing speed to spin-drying speed while the tub
is filled with water, means for setting a maximum spin-drying speed, a
motor supply control device, and electric speed regulator means
responsive to the setting means for controlling said motor supply
control device, an improved spin-drying control device comprising a
switch contact responsive to the level of water in the tub, and wherein
said setting means comprises a variable resistor, said speed regulator
being responsive to the setting of a circuit comprising said switch
contact connected to said variable resistor.

2. A device as claimed in claim 1 wherein said switch
contact is connected in parallel with said resistor, the contact being
closed when the tub is full of water, and the speed regulator response
is such that minimum resistance of the variable resistor corresponds to
minimum spin-drying speed.

Description:

The invention relates to a device for controlling the
spin-drying speed in a washing-machine which comprises a motor for
driving the drum, which motor can operate at two different speeds: a low
washing speed and a high spin-drying speed; switching means which
enable the passage from the washing speed to the spin-drying speed while
the tub is filled with water, a water level control device, a variable
resistor by means of which the maximum spin-drying speed can be
determined via a motor supply control device which is controlled by a
speed regulator.

From French Patent Specification No. 2,044,540,
to which U.S. application Ser. No. 34,727, filed May 5, 1970, assigned
to the assignee of this application, and now abandoned, corresponds, a
washing-machine is known in which a distributing speed is obtained
without the use of the additional speed changing device of a
conventional motor which, in addition to windings for the low and high
speeds, comprises a winding for each of the other speeds. In a machine
according to that patent the motor torque is predetermined in such a way
that when the electrical parameters which correspond both to the
spin-drying speed and to a limited torque are applied to the motor, the
motor speeds up and attains a speed which cannot increase as long as the
total mass consisting of the drum, the load of laundry and the water
contained in the tub is driven by the motor. The torque developed by the
motor is counter-balanced by the reactive torque as a result of said
total mass. Subsequently, while the tub still contains water, the drum
speed will increase to a given value for which the motor torque equals
the reactive torque produced by the braking effect of the water as a
result of the friction of water between the walls of the drum and the
tub. If the water level in the tub is maintained, said speed will remain
constant. By the partial or complete drainage of the water, thus
reducing the counter-torque, a new level or the spin-drying speed can be
attained. The electrical characteristics are substantially those of the
motor and its power supply device, while the mechanical characteristics
include the dimensions of the tub and the drum, the interior and
exterior profiles of the drum, and the distance from the wall of the tub
to that of the drum. The interior profile of the drum will influence
the laundry movement and thus the length of time that the drum speed is
kept constant for evenly distributing the laundry along the drum wall.
When
said first period of constant speed is passed, the acceleration of the
drum will have to be substantial so as to pass through the critical
speed range as rapidly as possible. In the critical speed range, which
varies per machine, the slightest unbalance of the load causes
vibrations whose amplitude may increase in time and which may cause
damage both to the housing and to the equipment attached thereto. Once
said range is passed, though the rotation of the drum is accompanied by
vibrations, they will be of sufficiently low amplitude not to present
any problems. Moreover, beyond said range of critical speed the drum
speed stabilizes and remains constant as long as the water level in the
tub remains constant. In the example of the aforementioned French
patent, said level is utilized for balancing, which is effected by the
addition of unbalance-compensation masses, generally by filling
compartments in the drum with water. The laundry distribution speed
level, which occurs at approx. 50 rpm, is maintained comparatively
briefly and its duration cannot be controlled in a simple manner because
it is produced by a torque which varies in time, and which is owing to
the unstable equilibrium obtained between the driving torque of the
motor at spin-drying speed and the reactive torque as a result of the
rotation of the total mass contained in the tub. In a washing-machine
which employs that feature, the speed level is unlikely to be
sufficiently large to ensure the optimum distribution of the mass of
laundry, which in itself is not a major drawback because a subsequent
balancing phase is provided. The main advantage is that the distribution
speed level is obtained without special means, simply through suitable
control of the driving torque of the motor at washing speed and
mechanical features such as the dimensions of the drum, of the tub, and
the water volume.

The invention evolves from the previously
cited Specification but its object is to obtain a speed level which is
maintained at a speed lower than the critical speed range as long as
desired. The balancing speed of 100 rpm to which the level of the
previous Specification automatically adjusts itself necessitates a
special construction which is conceivable when a machine is concerned
with a high spin-drying speed (600 rpm) which must have a particularly
good stability. Especially the water tightness of the tub must be very
good, in order to withstand the overpressures which may be produced
whilst the drum rotates at 100 rpm with 12 liters of water in the tub.

The
device according to the invention allows the speed level to be
controlled, requiring only a minimum number of additional elements. The
device consists of a single low-priced element: a contact which is
controlled by the water level, passing from the spin-drying speed with
filled tub to the spin-drying speed being effected automatically as the
water is drained from the tub.

The spin-drying speed control
device in a washing-machine of the type which comprises a drive motor
for the drum, which motor can operate at two different speeds: a low
washing speed and a high spin drying speed, switching means which enable
the passage from the washing speed to the spin-drying speed while the
tub is filled with water, a water level control device, a variable
resistor by means of which the maximum spin-drying speed can be
determined via a motor supply control device which is controlled by a
speed regulator, is provided by a speed regulator for a d.c. machine
drive motor, the device including a variable resistor which determines
the selected maximum spin-drying speed, said variable resistor being
short-circuited by a delayed contact.

In different embodiments:

said delayed contact which short-circuits the variable resistor is provided in the water-level control device.

said delayed contact is a contact of a device which controls the water level in the tub.

said delayed contact is constituted by a second water-level control device.

said delayed contact is a timer contact.

The following descriptions and drawing are given by way of example in order that the invention be more fully understood.

The sole FIGURE of the drawing is a simplified electrical diagram of an embodiment of the invention.
The
diagram shows a permanent-magnet d.c. motor 1. Said motor can be
energized via a bridge rectifier 2 which comprises two diodes and two
thyristors. The motor speed is regulated and controlled by a speed
regulator 3, which device controls the motor supply via the control
electrodes of the thyristors. A contact 4 which belongs to the timer is
connected in parallel with the contact of the water-level control device
5 (pressostat) in the closed position, i.e. tub filled with water. A
variable resistor 6 is included in series in the motor supply control
circuit and limits the control current to such a value that the motor
can attain the fixed spin-drying speed. The device for reversing the
direction of rotation of the motor is represented by the contacts 7, 8,
9, 10, which by the alternate closure of 7, 8 and 9, 10 change the
polarity at the motor terminals. The contact 12 which is included in the
motor supply circuit at the spin-drying speed belongs to the reversing
device and dictates the direction of rotation of the drum during
spin-drying.

The device according to the invention is in
particularly destined for a washing machine which comprises a motor 1
with a commutator which is supplied via a resistor 13, which resistor is
used for heating the suds. The value of said resistor is selected so
that the motor load may be as high as required without the permissible
motor current being exceeded and such that the motor can rotate at a
uniform speed, which speed decreases as the load increases. The motor
will then have a high current consumption and the substantial power
which is dissipated in the series resistor is used for heating the
water.

In an embodiment of the device for driving the drum of a
washing-machine, the permanent magnet d.c. motor 1 is supplied from the
electric a.c. mains by a diode rectifier bridge 2 via a control device
which in the diagram is represented by two thyristors. The application
or interruption of the d.c. supply is effected via the control
electrodes of the thyristor by means of a voltage which is produced by
the motor speed regulator 3. Said regulator comprises a reference
voltage generator, whose voltage is compared with the back e.m.f.
developed by the motor when it operates as a generator during the time
intervals in which it is not supplied by the rectified voltage. The
motor speed is limited by including a resistor 6 in the circuit of the
control electrodes of the thyristors. Generally, a variable resistor is
used which may or may not be accessible for the user and by means of
which the spin-drying speed can be adjusted to the desired value.

By
means of the variable resistor 6 the spin-drying speed can be adjusted
between two limits, a limit below and a limit above approximately 600
rpm. To obtain the maximum spin-drying speed, the resistance 6 must be
very high, while for the minimum speed it must be zero. The spin-drying
speed is fixed during starting of the machine at the same time as the
other washing parameters and does not necessarily correspond to the
lowest possible spin-drying speed. In one embodiment the minimum speed
is fixed at 100 rpm. This is advantageous when the motor torque can be
limited to the electrical characteristics which correspond to said
minimum spin-drying speed in such a way that the motor torque and the
reactive torque, owing to inter alia the mass of water in the filled
tub, are balanced around said speed. This is rendered possible by
short-circuiting the resistor 6 by a contact 14. The speed of the drum
in the filled tub will then be limited to that which corresponds to a
spin-drying speed, i.e. the lowest permissible spin-drying speed of the
machine.

As the variable resistor 6 should only be switched out
when the tub is filled with water, the contact 14 should be controlled
by the water level in order to ensure that the selected spin-drying
speed can be obtained when the tub is emptied.

The drainage of the tub is determined by the timer which controls the draining pump circuit.

In
one embodiment the contact 14 is a second contact of the water level
control device 5 (pressostat), the contacts 5 and 14 being mechanically
coupled. The elements which form the device which limits the spin-drying
speed with filled tub is therefore essentially a second contact 14 of
the pressostat, thus providing at least one closed contact for the
position with filled tub. A buffer resistor in the electronic device in
series with the variable resistor limits the lowest spin-drying speed
with filled tub, to a speed below the critical speed range, which range
varies in accordance with the type of machine for which the supply and
control device is destined.

The operation of the device is as
follows: it is assumed that the washing cycle is completed, and the
timer and reversing device have started the spin-drying cycle in the
preferred direction by contact 12 of the reversing device being opened.
The motor is energized via contact 4 of the timer and 5 of the
water-level control device. The contact 14 which is coupled to the
contact 5 of the pressostat is closed, for the tub is filled. In this
case, the voltage which is produced by the regulator 3 is applied to the
control electrodes of the thyristors and limits the speed to a value
below the critical speed range. Said speed is limited to 120 rpm, which
speed is below the critical speed range of the type of machine equipped
with the device.

After acceleration to spin-drying speed and
drainage of the tub (controlled by the timer) contact 14 opens, the
variable resistor 6 being no longer short-circuited, the speed increases
to the spin-drying speed which is selected and determined by the value
of the resistor 6.

The contacts 5 and 14 may be mechanically
coupled, but the contact 14 may also be incorporated in the pressostat
which comprises the contact 5. The contact 14 may alternatively be
constituted by the contact in "position filled tub" of a second
pressostat.

Thus, the speed-limiting device, simply by the
operation of the pressostat which is equipped with a second contact in
position filled tub or of a second pressostat, permits a gradual
acceleration to spin-drying speed with filled tub. Said gradual
accelerataion is effected from a minimum speed to spin-drying with empty
tub.

The advantages of such a device are, inter alia, a level
before spin-drying at a speed which is as slow as desired, and so
permits secondary effects on the watertight tub owing to turbulence of
the water to be reduced, thus allowing the use of construction materials
which are lighter and which render it easier to make the tub
watertight.

The contact 14 may alternatively be controlled by the timer, during starting of the draining pump or after a certain time.

IGNIS K12 (PHILIPS) AWF627/IG P.M. SYSTEM Switching control for a reversing motor of a washing machine:

A device for switching a d.c. motor of a washing machine. The drive
means of the reversing device is connected in series with a pressostat.
This circuit is connected in parallel with the terminals of the pump
contact; a terminal of the pressostat contact and a terminal of the
actuation contact of the supply module of the d.c. motor are connected.
The motor of the reversing device is connected in series with the pump
motor through which it is energized. 1.

A device for
switching a drum drive motor of a washing machine, comprising a pump
motor having a first line connection and a switch connection; a drum
drive motor; an electronic supply module having a first line connection
and a switch connection, and output connections; timer contacts,
including a pump motor contact having a second line and a motor
connection, and a spin cycle contact having a second line and a module
connection; a reversing switch assembly; means for connecting said drum
drive motor to said electronic supply module output connections via said
reversing switch assembly; means for driving the reversing switch
assembly having first and second input connections; a delay contact
having second line and motor connections; and means for connecting said
first line connections together and said second line connections
together and for connecting first and second line connections to a
source of electric power; wherein said pump motor contact motor
connection, pump motor switch connection and first input connection are
connected together, and said delay contact motor connection, spin cycle
contact module connection, electronic module switch connection and
second input connection are connected together, whereby said delay
contact and drive means for the reversing switch form a series circuit
in parallel with the pump motor contact, and said delay contact and spin
cycle contact are in parallel for supplying power to said electronic
control module.

2. A device as claimed in claim 1 wherein said delay
contact is a contact of a device which senses water level.

Description:

The invention relates to a method of and a device for
switching a d.c. motor to a high spin-drying speed. The motor drives the
drum of a washing-machine in an alternating fashion at a low washing
speed and continuously in a specific direction at a high spin-drying
speed. A timer assembly controls the sequence and the duration of the
washing operations and a reversing switch assembly which switches the
electric supply unit of the drive motor of the drum at washing speed in
an alternating fashion and at spin drying speed. Devices for switching
on the motor of the draining pump, for switching the supply of the drive
motor of the drum and for controlling the drive of the reversing switch
assembly are associated with the timer assembly and can short-circuit
devices which have the same functions but which are associated with the
reversing switch assembly thus rendering these inoperative by means
which are driven by the timer assembly. In the same way as similar
devices which are associated with the reversing assembly can short
circuit the said devices belonging to the timer assembly at a given
instant determined by the reversal of the rotating direction at washing
speed.
From French Pat. No. 2,058,524 a method is known of
switching a d.c. motor to spin-drying speed by means of four contacts of
a d.c. motor, which motor is powered from the a.c. mains via an
electronic module, and drives the drum of a washing machine. Said method
employs either a timer with one motor and electromechanical blocking of
the reversing cams, or a timer with two motors: one for the programming
section and one for the reversing section.
French Pat. No.
1,455,935 describes a device by means of which the reversing motor can
be stopped and consequently the spin-drying contacts can be actuated at a
precise instant of the reversing cycle and held in the actuated
position. This is achieved by connecting the reversing switch motor in
series with the spin-drying motor, which combination is connected in
parallel with the washing motor. The contact which is connected to a
branch of one of the phases of the supply mains, which branch is
disposed between the reversing switch motor and the spin-drying motor,
is locked to the energizing contact of the washing motor and functions
oppositely.
The methods and devices described in the two patent
specifications thus permit the spin-drying cycle to be started at a
precise instant of the reversing cycle when the desired contacts of the
reversing means are closed. The reversing means then stops in this
position during the entire spin-drying cycle, thus ensuring a safe
operation. Moreover, it is impossible to damage the machine assembly and
the electronic module by an incorrect operation. As a matter of fact,
the machine would become highly unstable when by operating the timer
spin-drying is allowed while the preferred direction of rotation of the
drum is not correct. The sudden reversal of the polarity of the motor
and its power supply might lead to the immediate breakdown of the
electronic components of the power supply unit. As the reversing means
itself controls the acceleration to spin-drying, irrespective of the
setting of the timer, this yields a greater mechanical and electrical
safety.
However, there is still a risk if the reversing means is
activated too soon after completion of the spin-drying cycle. One of the
characteristics of a permanent-magnet motor is that it also constitutes
a generator, that is it can produce a voltage which is proportional to
the rotor speed. Thus, during the entire deceleration period after
completion of spin-drying a voltage appears at the terminals of the
brushes which decreases gradually. For example, in said French Pat. No.
2,058,524 the voltage at the motor terminals is of the order of 200
Volts. Immediately after the electronic module is switched off, the
motor keeps rotating as a result of its inertia and that of the loaded
drum. This period of deceleration may last several tens of seconds.
Throughout said period the voltage at the terminals decreases gradually
from 200 V to 0 V. If it is assumed that the reversing means when
started again rapidly changes over the two opposite contacts, the supply
voltages and the motor voltages are suddenly reversed. This results in a
short circuit which is the more violent because the voltage is high.
The
invention is based on the previously described devices and its object
is to avoid short-circuits that would occur if the reversing switch
means were started again while the drum had not yet stopped. Moreover,
it has the advantage of greater simplicity because it employs existing
elements of the washing-machine.
According to the invention, the
switching method is characterized in that the control of the reversing
switch assembly is applied in series with the pump motor drive.
According
to the invention, a device for switching a d.c. motor of a washing
machine to spin-drying speed, comprises a timer assembly and a reversing
switch assembly whose drive means are independent, make or break
contacts for the pump motor, for the electronic supply module, for the
drive motor of the drum and for the drive of the reversing switch
assembly, the circuits constituted by a contact of the pump motor which
is controlled by the timer in series with said pump motor and by an
energizing contact of the electronic d,c. supply module of the drive
motor of the drum in series with said power supply being supplied in
parallel from the a.c. mains, wherein a circuit formed by a delayed
contact in series with the drive means of the reversing switch assembly
is connected in parallel with the terminals of the contacts of the pump
motor, the terminal of the delayed contact which also forms a terminal
of the drive means of the reversing switch assembly and the terminal of
the energizing contact of the electronic module, which terminals are not
permanently connected to a phase of the a.c. mains, being
interconnected.
The delayed contact is constituted by the device which senses the water level in the tub of the machine.
In
order that the invention be understood more fully reference is made to
the following descriptions and Figures which are given by way of
example.
FIG. 1 is a schematic diagram of a device for stopping
the reversing means in a specific position in accordance with the prior
art.
FIG. 2 is a schematic diagram of a device according to the invention.
FIG.
1 represents the device which controls the rotating direction of a
permanent-magnet d.c. motor described in Franch Pat. No. 2,058,524, the
reversing device being stopped during acceleration to spin-drying speed
by selection of the contacts of the reversing switch means for a
preferred direction of rotation.

The drive motor 1 of the drum is
d.c. motor powered by an electronic module 2 which consists of a
semi-conductor rectifier bridge and a reversing switch assembly of
contacts 3, 4, 5, 6.
To reverse the running direction, the
polarity at the motor terminals is reversed by closing the contacts 3
and 5 or 4 and 6 respectively in the desired rhythm. To increase the
speed of the drum from the washing speed (approx. 50 rpm) to the
spin-drying speed (100 to 600 rpm) the supply current at the terminals
of the drive motor is varied and the reversing switch means is put out
of action, which necessitates the use of independent drives for the
timer and for the reversing switch means. Acceleration to spin-drying
speed in a preferred direction is achieved by the following combination
of contacts (the contacts represented by two dashes are associated with
the reversing means and those represented by a single dash with the
timer): the reversing contact 7 controls the power supply 2 of the motor
1, when 7 is closed the current which is supplied to the motor
corresponding to the low washing speed; when it is open said current
corresponds to the spin-drying speed. The contact is open at a specific
position of the reversing cycle (for example when 3 and 5 are closed).
In order to ensure a specific rotating direction during spin-drying, the
motor 10 of the reversing switch means is stopped by opening contact 8.
Reversing contact 9 which energizes the pump for draining the tub 11,
is closed when the motor 10 of the reversing means has stopped. Contacts
7' 8', 9' are timer contacts which ensure normal operation if no
spin-drying is required. Contact 12 is the timer contact which controls
the draining cycle.
The operation of the device is as follows:
during washing, contacts 7, 8, 9 are short-circuited by contacts 7', 8',
9' which are controlled by the timer; while the reversing means
rotates, the d.c. motor rotates in accordance with a specific rhythm and
in the two directions of rotation.
During spin-drying,
acceleration is effected in two steps. First of all, the timer contacts
7', 8', 9' open. Contact 8 of the motor of the reversing means remains
closed, the d.c. motor is still supplied with the "washing" voltage, the
motor of the reversing means keep rotating.
Subsequently, at a
given instant of the reversing cycle (when 3 and 5 are closed) the motor
of the reversing means stops because 8 is open and spin-drying
commences because 7 is open.
From the above description of the
operation it appears that if at the end of the spin-drying cycle the
machine is immediately re-started, the motor of the reversing means will
be re-energized and rapidly switches the two contacts opposite 3 and 5,
that is 4 and 6, and the supply voltages and the motor voltage are
suddenly reversed. This causes a short-circuit which becomes the more
severe as the voltage supplied by the motor is higher.
The
invention provides a method and a device which assure absolute safety
when spin-drying is discontinued and which permit the previously
described circuits to be simplified.
In FIG. 2 elements which are equivalent to those of the previous embodiment have the same reference numerals and functions.
The operation of the various elements is as follows:
During
the washing-cycle, contacts 12 and 13 of the timer are open and a delay
means 14 closes the circuit a certain time after the machine is
started. The motor 1 is energized by the electronic module 2, whose one
of terminals is connected directly to one phase of the mains, and the
other terminal to the second phase of the mains through contact 14;
contacts 7 and 7' are open, thus allowing the motor to be energized with
a voltage corresponding to the washing speed. The motor of the
reversing means 10 is energized through contact 14 which is closed and
the pump motor 11. As the impedance of the motor of the reversing means
is high relative to the impedance of the pump motor, the pump motor
cannot start. The motor 1 alternately rotates in either direction at the
washing speed.
When the timer advances to the spin-drying cycle,
contact 12 which is controlled by the timer closes, pump motor 11 is
started, contact 7 closes when contacts 3 and 5 which define the
preferred direction of rotation are closed and, spin cycle contact 13
also closes and short-circuits contact 14 which opens after a relatively
short time. At the same instant the motor of the reversing means 10 is
stopped and maintains the position of contacts 3 and 5 for the duration
of the spin-drying cycle.
When the spin-drying cycle is
discontinued because the electronic module 2 is switched off, contacts
12 and 13 of the timer open, motor 10 of the reversing means remain
stopped and pump motor 11 are stopped. The motor 10 of the reversing
means then cannot be started until after the delay contact 14 has closed
the circuit. This allows motor 1 to come to a complete standstill
before commencing with a new cycle of the revolutions.
In an
embodiment of the washing-machine in which switching to spin-drying
should take place with filled tub, the delay means is constituted by the
pressostat contact.
Apart from the advantages of assuring
change-over to spin-drying in a specific direction of rotation,
independently of any change in timer setting, the pump motor 11 is
switched on by a contact at a previously determined instant and without
any other means short-circuits the motor 10 of the reversing means.
Consequently, it is not necessary to use one or two additional contacts
as described in French Pat. No. 2,058,524. The pump contact 12 alone
performs the functions of controlling the pump and blocking the
reversing means.
A device embodying the method according to the
invention employs the arrangement of the elements as shown in FIG. 2 and
in said device the function of the delayed contact 14 is performed by
the pressostat (in the case of a machine which changes over to
spin-drying with filled tub), contact 12 of the timer being an existing
contact because this serves for starting the pump motor.
Thus,
connected in parallel with the mains terminals are the circuit formed by
contact 12 of the pump motor in series with the pump motor 11 and the
circuit formed by the spin cycle energizing contact 13 of the electronic
module 2 and the electronic module. Parallel connected with contact 12
is the circuit with the delayed contact 14 (pressostat) in series with
the motor 10 of the reversing means (or any other means which permits or
prevents the reversing section of the timer from being driven. The
delayed contact 14 and the motor of the reversing means 10 are
consequently connected in series with the motor 11 of the draining pump.
The terminals of contacts 13 and 14, which are not permanently
connected to the phase of the mains, are connected.
This
arrangement, compared with the arrangement described with reference to
FIG. 1 allows four contacts (two reversing contacts and two timer
contacts) to be dispensed with, which apart from providing operational
safety results in a simplification of the timer-reversing device and
consequently a substantially reduced cost price.

A device for avoiding unbalance during acceleration to spindrying. A
water level sensor has an additional contact through which a control
voltage which is derived from a motor speed regulator is fed, and
interrupts the motor supply if the drum speed decreases below a
predetermined value. Spindrying cannot commence until after the tub is
filled and an operating sequence at washing speed has taken place.

1. A device for
preventing excessive imbalance in a clothes washing machine, comprising a
drum driving motor, means for supplying voltage to the motor,
regulating means sensitive to rotational speed of said motor for
providing an output electrical control signal in response to said speed
being below a predetermined speed, means for controlling voltage
supplied by said supply means in response to an electrical control
signal input, a water level switch contact for sensing a tub empty
condition, an operating function controller contact for selecting a spin
drying function, and means connecting said water level sensing contact
and said operating function contact between the regulating means output
and said voltage controlling means input such that voltage supplied to
said motor will be controlled in response to said speed sensitive signal
only when said spin drying function is selected and a tub empty
condition is sensed.

2. A device as claimed in claim 1, wherein said voltage
supplying means is blocked by said electrical control signal.

3. A device as claimed in claim 1, wherein said contacts
are in electrical series connection, the water level switch being
closed in response to a tub empty condition, said regulating means
output signal is additionally responsive to comparison of motor speed
with a spindrying speed, and said voltage supply is blocked by an
electrical control signal input corresponding to said motor speed being
below said predetermined speed.

Description:

The invention relates to a device for preventing an unbalance
in washing machines during spindrying, which becomes operative after a
voluntary or involuntary interruption of the operation of the machine,
or after a decrease of the spindrying speed of the drum below a
predetermined level, by providing for a sequence of alternating
rotations of the drum at the low washing speed before the acceleration
to the high spindrying speed.
During an interruption of the
operation of a washing machine, owing to for example, a power failure or
a voluntary stop during the spindrying cycle, the load which was
distributed by the preceding washing cycle with alternating rotations
comes off the drum wall and collects at the bottom of the drum. This may
also happen if the drum speed decreases below a certain level. The
laundry is then more or less dry and its mass may vary within rather
wide limits. Accelerating again to the spindrying speed may have serious
consequences because of unbalance which gives rise to substantial
displacements of the tub-motor assembly, which will then hit the walls
of the machine. The effects of the unbalance are especially marked in
light weight machines having a low balancing mass and in which
acceleration to spindrying is effected with a filled tub. In that case,
the critical speed is always passed when the tub is still filled with
water, i.e. when the mass of the tub-motor assembly is still
substantial, and as rapidly as possible in order that vibrations of a
high amplitude cannot build up.

From French Pat. Specification
1,530,872 a control device for the drive motor of the drum of a washing
machine is known which, when a spindrying cycle is controlled
independently of the washing cycle or after voluntary or involuntary
stoppage of the machine, causes said motor to start with a cycle of
alternating rotations at washing speed so as to tumble and distribute
the load. Said device moreover comprises a delay means constituted by a
pressostat switch sensitive to water level in the tub and a bimetal
which is heated by a timer-controlled circuit, which prevents starting
of the spindrying cycle while the tub is still filled with water. This
known embodiment is an approach towards the solution of the problem of
the unbalance during acceleration to spindrying after a stop. However,
switching to alternating rotation at washing speed cannot always lead to
a satisfactory distribution, especially when the laundry has hardly
dried; i.e., at the very beginning of the spindrying cycle. This is also
the case when the user employs the machine for spindrying only.
In
a device according to the invention, a contact of a water level control
device is connected in series in a branch of the circuit of a motor
regulating device, which controls the electrical current to the motor,
said contact being closed when the tub is empty.
In another
embodiment said contact is in series with a second contact associated
with the timer, which operates simultaneously with a timer contact
associated with the spin-drying made.
The following descriptions and drawing are given by way of example in order that the invention be more fully understood.

The single FIGURE of the drawing is a circuit diagram of a device according to the invention.
French
Pat. Specification 1,530,872 describes a device which can be employed
in a machine in which spindrying can apparently commence whilst the tub
is empty. Moreover, devices are provided for changing over from the
washing speed to the spindrying speed when the washing speed reaches 80
to 85% of its rated speed. The drum then accelerates to high speed. This
operation is effected each time that the power supply is restored after
stopping. It is to be noted that the distribution of the laundry is
effected while the tub is empty, the pressostat allowing acceleration to
spindrying only while the tub is empty.
According to the
invention a laundry distribution cycle, known per se from the French
Pat. Specification No. 2,044,540, "Spindrying with filled tub", is
performed in the presence of water, so as to obtain an optimum
distribution. This is effected each time that the machine is stopped
voluntarily or owing to a power failure, or when the spindrying speed
has dropped below a previously determined value. The distribution cycle
is obtained by filling the tub with water to a sufficient level,
followed by a cycle of alternating rotations at washing speed for a
given time, after which the timer causes the motor to accelerate to
spindrying speed, while the tub is still filled with water, and
simultaneously the pump is energized to reduce the water level and allow
acceleration to the selected spindrying speed.
The use of a d.c.
motor for driving the drum in series with the heating resistance allows
a balance to be obtained between the maximum permissible speed and the
moment of resistance. Acceleration to spindrying with filled tub
presents no problems with such a d.c. motor, because by an appropriate
selection of the heating resistance which is connected in series with
the motor the speed is automatically limited to a value equal to the
maximum speed which is permissible without overflowing. The
permanent-magnet d.c. motor 1 used in the embodiment shown in the
drawing is energized from the a.c. mains via a bridge with diodes and
thyristors 2. The direct voltage supplied by said bridge is controlled
by a regulating device 3 of any type well-known in the art which
compares the back-e.m.f. of the motor, during the periods when said
motor is not energized and behaves as a generator, with a specific
reference voltage for the washing speed and the spindrying speed. Such a
regulator is shown, for example, in U.S. Pat. No. 3,640,098. Said
comparison results in a voltage which is applied to the control
electrodes of the thyristors and thus influences the motor supply. The
voltage thus supplied to the motor passes via contacts which are
disposed on cams which are fixed on a shaft which is driven by a motor
(not shown) forming the reversing device and enabling the alternating
rotation of the motor by changing the polarity of the supply voltage at
the motor terminals.
The device according to the invention
comprises two elements, of which one is external and the other is
included in the power supply. This is shown by the diagram. By the
closure of the contact 4 the pressostat of the machine energizes the
motor 1 and the heating resistance 6 in series when filling is
completed. A second pressostat contact 5 ensures that the rectifying
bridge 2 which supplies the motor can be controlled when it is closed,
i.e. when the tub is empty. The closure of the contact 5 enables the
control voltage from the regulating device 3 to be applied to the
control electrodes of the thyristors.
The contact 5 may be
incorporated in the pressostat 4 as shown in the present embodiment or
may form an assembly which is separate from the pressostat and which in a
similar way as the pressostat responds to the water level in the tub.
It is simpler to couple said contact mechanically to the pressostat
contact.
The contacts 7 and 8 are associated with the timer and are closed during spindrying.
The operation of the device is as follows:
During
acceleration to spindrying, while the tub is filled with water, the
contact 4 energizes the motor 1 via the rectifying bridge 2.
Acceleration takes place. During this time, the rectifying bridge 2
which forms the power supply operates normally because the tub-empty
contact 5 is open and does not control the control electrodes of the
thyristors.
After the tub is emptied and when the speed is
sufficient (above 80 rpm for the drum) contact 4 opens and contact 7 of
the timer ensures the continuation of the motor supply. At the same time
the contact 5 closes. The control voltage from the regulator 3 is then
fed via the contact 8 to a device for controlling the supply voltage of
the motor which maintains the spindrying speed.
If owing to some
cause the motor speed, and thus the speed of the drum, drops below a
predetermined value, the contacts 5 and 8 remaining closed, the control
voltage from 3 interrupts the power supply in the present example by
turning off the thyristors. The motor stops and thus the risk of
instability owing to the occurrence of an unbalance as a result of a
change in distribution of the load is eliminated.
The power
supply control device which is controlled by the voltage from the
regulating device 3 is not rendered operative during the acceleration
phase, for in that case the power supply would be permanently cut off
because the motor speed is below the predetermined threshold (100 rpm for
the drum).
As the pressostat which comprises 4 provides a delay,
it initially allows the acceleration of the motor and the clearance of
the threshold. In a second phase, when the tub is empty, contact 5
allows the power supply to be blocked if the speed becomes lower than
said threshold.
Thus, the device employs a power supply which
comprises a blocking threshold, a pressostat which controls the closure
of a contact 5, when the tub is empty in series with a contact 8 which
is associated with the timer and which is closed during spindrying.
The
combination of said elements thus prevents restarting in the spindrying
mode if the voltage at the motor terminals has been cut off.
Thus, the stability of the machine is ensured when:
the
user stops the machine during spindrying and starts it again after a
certain time during which the laundry can collect at the bottom of the
drum.
the supply voltage of the machine has been cut off.
an intermittent defect of electrical contacts occurs in the control elements of the machine.
the
user performs a forbidden operation by setting the timer knob to the
spindrying cycle whilst the tub is empty and the complete starting
process with water cannot be performed.

A method of controlling the operation of a d.c. motor of a washing
machine by energizing or de-energizing a reference voltage generator.
The back-e.m.f. of the motor is compared with the reference voltage. The
a.c. supply of the generator is controlled by contacts of detectors for
the operating conditions of the machine, such as temperature of the
suds or of electronic components, unbalance, opening of the door etc.

1. A method of
controlling a d.c. motor of a washing machine in dependence on motor
speed and at least one other parameter, by energizing a motor from a
controlled rectifying bridge circuit supplied from an alternating
current source; supplying a control signal to said bridge circuit from
an electronic speed regulator; generating a motor stop signal in a
comparator by comparing a back-e.m.f. signal from the motor with a
reference voltage from a reference voltage generator; and applying a
motor de-energize signal to said regulator in response to a low speed
condition and in response to a given other condition; wherein said step
of applying a de-energizing signal in response to a given other
condition comprises detecting said given other condition and controlling
a switch contact responsive to said given condition, and supplying
alternating current power to said reference voltage generator from said
alternating current source through said switch contact.

2. A method as claimed in claim 1, wherein upon
occurrence of said given condition, said switch contact is closed so as
to apply alternating current power to said reference voltage generator,
and said motor de-energizing signal is applied to said regulator when
motor speed is below a given speed while power is applied to said
reference voltage generator.

3. A method as claimed in claim 2, wherein said other
condition relates to water level in a tub of the machine, and said
switch contact is closed when said tub is empty.

4. A method as claimed in claim 2, wherein said
reference voltage generator includes a plurality of input alternating
current power connections; and a respective plurality of switch contacts
are responsive to a plurality of other conditions, each input
alternating current connection providing power to generate a unique
reference voltage level.

5. A method as claimed in claim 4, wherein one switch
contact is closed in response to detection of low water temperature.

6. A method as claimed in claim 5, wherein a second
switch contact, associated with generation of a reference voltage
corresponding to a higher motor speed than that associated with the low
water temperature detection, is closed in response to a tub empty
condition sensed by a tub water level detector.

Description:

BACKGROUND OF THE INVENTION
The invention
relates to a method of controlling a d.c. motor (POLYMOTOR ITALIANA [PHILIPS] 8219 440 01351) of a washing machine in
dependence on a parameter which is not exclusively related to motor
speed. In such a method the motor is energized from an alternating
current supply through a rectifier bridge which comprises two diodes and
two thyristors, the thyristors being controlled by a signal which is
supplied by an electronic speed regulator. During at least one specific
operating cycle of the machine the timer switches on a control device,
which supplies a motor de-energize signal to the regulator for stopping
the motor when the motor speed drops below a certain value, the control
device being actuated by a motor stop signal supplied from a comparator
which continually receives both the back-e.m.f. voltage of the motor and
a rectified reference voltage from a reference voltage generator.
Such
a device for controlling the operation of the motor is particularly
useful in a machine which accelerates after a laundry distribution
cycle. Such a method of starting up is employed if the weight of the
machine is to be reduced or if the spindrying speed is to be increased.
It is then necessary to take special care that the mass of laundry is
distributed as uniformly as possible along the walls of the drum so as
to avoid unbalance. When the mains supply of the machine is interrupted,
the motor may either stop because the failure lasts some time, or may
slow down when the failure is very brief. In the first case the laundry
drops again onto the bottom of the drum; and during speeding up the
unbalance will become more severe, depending on the wetness of the
laundry. In the second case the loss of speed of the drum may be such
that the result will be the same as if it had stopped.

Control of
the motor by the control device in the event of a voltage failure is
based on the comparison of two voltages: a negative voltage produced by
the back-e.m.f. of the motor when the motor has reached its normal
operating condition for the relevant cycle and a full-wave rectified
reference voltage which is derived from the supply circuit of the
regulator and an antihunting device. The reference voltage is adjusted
to a value lower than that of the BEMF voltage which corresponds to the
drum speed at which the laundry no longer remains at the periphery of
the drum.

SUMMARY OF THE INVENTION
It is an
object of the invention to provide a method of controlling a d.c. motor
(POLYMOTOR ITALIANA [PHILIPS] 8219 440 01351) of a washing machine in dependence on a parameter which is not
exclusively related to the motor speed and to achieve this by switching a
reference voltage generator on or off. The various detectors for
parameters such as the motor temperature or the temperature of
electronic components, the temperature of the suds, opening of the door,
the water level, tub displacement etc. have at least one make or break
contact in series with the a.c. supply circuit of the reference voltage
generator.
The method according to the invention of controlling a
d.c. motor of a washing machine is characterized in that the control
device is activated by modifying the supply voltage of a reference
voltage generator, said modification being controlled by at least one
contact of at least one detector for a variation of an operating
parameter of the machine.
The method is further characterized in that the reference voltage generator is energized when the tub is empty.
The
device embodying said method is characterized in that a reference
voltage generator comprises at least one switched a.c. input which
corresponds to at least one predetermined reference voltage at the
output.

In various embodiments:
at least one make or break
contact for the a.c. supply of the reference voltage generator belongs
to at least one detector for an operating parameter of the machine,
at
least one make contact of the a.c. supply of the reference voltage
generator is the tub-empty contact of a detector for the water level in
the tub of the machine,
at least one make or break contact of the
power supply of the reference voltage generator is a contact of a
detector for the amplitude of tub movements,
at least one make or
break contact of the power of the reference voltage generator is a
contact of thermal senser which controls the temperature of the washing
water,
at least one make or break contact of the power supply of
the reference voltage generator is a safety contact for the door of the
washing machine,
at least one make or break contact of the power
supply of the reference voltage generator is a contact of a thermal
senser which is disposed on an element of the washing machine whose
heating resistance is connected in series with the motor supply, which
element is subject to overheating as a result of a malfunction.
The following descriptions and drawings are given by way of example in order that the invention may be more fully understood.

BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block diagram of a prior-art device.
FIG. 2 is a block diagram of a control system according to the invention.
FIG. 3 is an electronic circuit diagram of the reference voltage generator, comparator and control unit of FIG. 2.
FIG. 4 is a block diagram of a device for controlling a motor of a washing machine in dependence on several parameters.

DESCRIPTION OF THE PREFERRED EMBODIMENTS:

FIG.
1 represents a d.c. motor control system in accordance with a device
described in U.S. Pat. No. 3,939,673 issued Feb. 24, 1976 to the instant
applicant. The sole object of said method is to avoid the unbalance
which occurs in washing machines during spin-drying after a voluntary or
involuntary interruption of the operation of the machine or after the
spindrying speed has dropped below a predetermined value, said method
consisting of refilling of the tub with water and acceleration to
washing speed before acceleration to spindrying speed with the tub still
filled with water.
A permanent-magnet d.c. motor (POLYMOTOR ITALIANA [PHILIPS] 8219 440 01351) 4 is energized
from the a.c. mains 1, 2 through a rectifier bridge 5 which comprises
two diodes and two thyristors. The rectifier bridge 5 is connected in
series with an immersion heater 3. The thyristors of the bridge 5 are
controlled by a regulator 6 which compares the voltage produced by the
back-e.m.f. (BEMF) of the motor when said motor is not energized, with
reference voltages for the washing and spindrying speeds. The input of
the reference voltages to the regulator 6 is represented by the line 13
and that of the BEMF voltage by the line 14. In order to require that a
re-starting cycle proceed only with filled tub so as to avoid unbalance
if an interruption of the power supply of the machine, has occurred, a
control device 7 constituted by, for example, a transistor, receives its
actuating, or motor stop, signal from a comparator 8. The comparator 8
via the lines 13 and 14 respectively receives a d.c. reference voltage
and the voltage produced by the back-e.m.f. of the motor. When the value
of the BEMF voltage of the motor becomes lower than that of the
reference voltage, the control device via the regulator 6 causes the
thyristors of the power supply 5 to be cut off and hence the motor is
stopped. In order to allow the motor to speed up to spindrying and to
avoid power supply blocking control before the motor has reached a speed
which suffices to avoid blocking of the power supply, the output of the
control device is connected to the regulator through the contacts 9 and
10. The contact 9 is mechanically coupled to the contact 11 of the
pressostat which is only closed when the tub is empty; the contact 10 is
a timer contact which is closed for the spindrying cycle. The contact
12 which belongs to the timer is closed during spindrying and enables
the motor to be supplied, ensuring that power supply is continued when
the contact 11 of the pressostat opens after drainage.
Thus, such
a device allows two parameters to be controlled: the motor speed and
refilling of the tub with water. The other parameters such as the
temperature of the suds, the temperature of the electronic components or
of the motor, or the amplitude of the vibrations of the tub can only be
controlled by means of detectors whose contacts control the main power
supply of the machine. The same applies to a door opening safety device
which also steps the machine when the door is opened during operation.
It is not possible to achieve the previously outlined goals by
connecting said contacts in series with the output of the control
device, for the control signal is very weak; therefore, the method
according to the invention enables the motor to be blocked by means of
these different parameters which no longer act on the weak signal
supplied by the control device but rather act on the supply of the
reference voltage which is an input to the comparator.

FIG. 2
shows a block diagram of a device embodying the method according to the
invention. In this diagram the devices and elements which resemble those
in the known arrangement have been given the same reference numerals.
The permanent magnet d.c. motor 4 is supplied from the a.c. mains 1, 2
through a rectifier bridge 5 which comprises two diodes and two
thyristors. The rectifier bridge 5 is connected in series with the
immersion heater 3. The thyristors of the bridge 5 are controlled by a
regulator 6 which compares the voltage produced by the BEMF of the motor
with reference voltages for the washing and spindrying speeds. The
input of the reference voltages to the regulator 6 is represented by the
line 13 and that of the BEMF voltage by the line 14. The control device
7, which in a known embodiment is constituted by a transistor, receives
a voltage at its base which is supplied by the comparator 8. The
comparator 8 receives the BEMF voltage from the motor over the line 14,
and compares that voltage with a rectified reference voltage supplied by
the reference voltage generator 15. The reference voltage generator 15
is supplied with alternating current from the terminal 17 through the
detectors 16 for detecting operating parameters of the machine other
than the speed of rotation of the motor and, finally, through a contact
10 which belongs to the timer rectified-voltage generator to be switched
on or off.

FIG. 3 shows a circuit diagram of the control unit of
the electronic regulator. The devices of the block diagram in FIG. 2
are delimited by dash lines and have the same reference numerals. Thus,
the control device 7 is constituted by a transistor whose collector is
connected through a resistor 19 to provide a motor-de-energize signal to
a control electrode of the tetrode thyristor (not shown) of the
regulator 6, the emitter receiving the supply voltage from the motor.
The
base of the transistor 18 is supplied with a voltage which is the sum
of the voltages across the resistors 20 and 23, which come from the
+terminal of the motor supply, and the voltage which is the result of
the comparison of the BEMF voltage of the motor (line 14 and resistor
21) with a reference voltage obtained from the generator 15 through the
resistor 22. Capacitors 24 and 25 are polarized capacitors and the diode
26 is a protection diode.
The reference voltage generator 15 is
shown with two inputs 27 and 28. Each of these inputs includes a diode
29 which rectifies the alternating voltage applied to its terminals
through the contacts of the detector switches 16. Each branch of the
voltage generator constituted by the elements 29,31 and 30, 32 supplies a
different reference voltage. Thus the branch 27,29,31 supplies a
rectified voltage which is equivalent to the BEMF voltage of the motor
at a speed which at least equals 70 r.p.m., while the branch 28,30,32
supplies a voltage equivalent to the BEMF voltage of the motor at some
given speed lower than 50 r.p.m.
These inputs of different value
of the reference voltage generator are applied by the contacts of the
detectors 16 depending on whether the motor speed during washing (50
r.p.m.) or during sprindrying is to be controlled.

The operation of the devices 7,8 and 15 of FIG. 3 is as follows:
The
circuit will be considered which is constituted by the terminal 17, the
contact 33, the terminals 27, the diode 29 and the resistor 31 (the
capacitor which is shown but which has no reference numeral is a
timing-base capacitor and is irrelevant for the description of the
operation). When the terminal 27 is not energized, the base of the
transistor 18 receives a negative voltage produced by the BEMF of the
motor. As a result, the transistor remains cut off permanently and the
control of the thyristors which are connected to the collector through
the resistor 19 is not influenced: the power supply functions normally.
After
speeding up to spindrying, the application of an alternating voltage to
the terminal 27 has no effect, for the motor voltage which is supplied
over line 14 and resistor 21 is more negative than the opposing voltage
which is positive because rectification by the diode 29, and the
transistor 18 remains cut off.
If the mains voltage at the
terminal 27 is interrupted for a time which is sufficiently long for the
BEMF to assume a low value (simply by the motor slowing down), there
will be an instant at which the positive voltage supplied through
circuit 29,31 and 22 becomes more significant, and a motor stop signal
is applied to the base of transistor 18: the transistor 18 then
conducts. Thus, it blocks the operation of the thyristors and
consequently the motor supply.
If the machine is to be
re-started, it suffices to interrupt the circuit which supplies the
terminal 27, for example by re-filling the tub, and the cycle is then
repeated. The afore-described operation corresponds to a voltage failure
protection and ensures that the motor cannot speed up again to
spindrying speed without a prior laundry distribution cycle, which may
be qualified as internal control of the motor supply.
The devices
provided enable external control of the power supply by means of the
contacts of a detector for variations of an operating parameter of the
machine. Typical parameters are for example the water level, the
temperature of the suds, the displacement of the tub, opening of the
door, blocking of the drum or motor.

The dash line 10 (FIG. 3)
between the detector elements 16 and the rectified-voltage generator 15
corresponds to contact 10 in FIG. 2 and belongs to the timer.
Control
of the operation of the motor in dependence on the water level in the
tub may be obtained, when the contact 33 is assumed to belong to a water
level sensor or pressostat. If the thyristors of the motor supply
should not be blocked as soon as the machine speeds up to spindrying, it
is necessary that the motor has reached a certain speed (which has been
fixed at approx. 600 r.p.m., or 80 r.p.m. for the drum of the
machine), so as to ensure that the BEMF of the motor, which comes from
21 and 23, exceeds the reference voltage. To accomplish this, terminal
27 is not energized during said acceleration phase. For this purpose,
the following switching process is realised: the terminal 27 is
energized through the contact 10 which belongs to the timer and which is
closed during spindrying only. The high-level pressostat of the machine
has two contacts, of which one contact 33 corresponds to an empty tub
and a second contact, not shown, corresponds to a filled tub. The
contact 33 is connected in series with the contact 10 of the timer.
During
acceleration to spindrying, the pressostat is in the filled-tub
position, i.e., contact 33 is open. The machine speeds up normally.
After some tens of seconds, while the tub is gradually filled, the
pressostat returns to the empty position, and contact 33 is then closed.
Through contact 33 and contact 10 of the timer the alternating voltage
is applied to input terminal 27 of the reference voltage generator. Two
cases are to be considered:
the speed of the drum is higher than
80 r.p.m.; in this case the voltage failure has no effect, and the
machine continues to speed up to spindrying speed,
the speed of
the drum is lower than 80 r.p.m.; in this case the machine is blocked
and it is impossible to start the machine except if 33 is open, i.e.
when the tub is full. If starting in the spindrying mode is attempted
with an empty tub, whilst contact 33 is closed, the system is blocked at
once and the machine cannot start.
Control as a function of the
temperature of the suds is applied when the laundry should not be
stirred during special cycles. For example, for woollens, the washing
movement should be minimal. The reference voltage generator will be
energized at 28 through the timer contact 10 (FIG. 3) and through a
contact 34 which in this case belongs to the thermostat. Said thermostat
contact opens when the required temperature is attained, the motor
supply thus being blocked until the temperature is reached. Once the
washing water has the desired temperature, contact 34 of the thermostat
opens, the alternating voltage at terminal 28 cuts out and the motor is
immediately started for the next operations at washing speed.
In a
similar way, the motor can be controlled in dependence on the
displacement of the tub. It is known that instabilities owing to an
incorrect distribution of the lead of laundry in the drum occur at
specific speeds, which are called critical speeds. In order to avoid
damage to the machines, it is necessary to stop the machine very rapidly
when the amplitude of displacements of the washing unit are excessive.
For this a contact, represented by contact 33 in FIG. 3, is disposed at a
specific location in the path of the washing unit during substantial
displacements, which will result in automatic stoppage in dangerous
cases. As the contact 33 is a self-releasing contact (i.e. it returns
immediately to its original position, which is "contact open"), it is
evident that when the washing unit actuates the contact 33, a short
pulse is applied via contact 10 of the timer to the rectified-voltage
generator and subsequently to the motor supply, the motor being stopped
immediately. The conventional methods of acceleration to spindrying can
then function normally.
Control of the motor supply when the door
is opened is achieved in the same way as in the previous case, by
disposing a circuit breaker 33 or 34 on the door of the machine. In
accordance with the washing cycle of the machine, the machine is stopped
through contact 33, if the machine is in the spindrying mode, and
through contact 34 during the washing mode.
It is equally
possible to ensure that the power supply circuit of the motor is
protected when the drum is blocked. It is known from French Patent
Specification No. 2,009,665 or British Patent Specification No.
1,354,367 that the circuit of the permanent-magnet motor is protected
both by the limitation of the current owing to the series resistance
and, as known from U.S. Pat. No. 3,638,090, by a thermal protection
device consisting of a temperature detector which is disposed underneath
the heating element and which interrupts the power supply when the
temperature exceeds a preset threshold. The same result can be obtained
by including the contacts of the temperature detector in the power
supply circuit of the reference voltage generator at 33 or 34 or in the
two branches (FIG. 3). For example, if the detector is disposed close to
the heating element, or in the interior of the motor or on the heat
sinks of power elements of the motor supply, the motor supply will be
blocked electronically when the temperature becomes too high, as soon as
the contact of the detector is closed.

The method and the device
according to the invention, moreover enable protection of the machine
in the event that the rotor of the motor is blocked. The operating
principle has been described hereinbefore of pressostat control which
allows acceleration to spindrying only when the tub is filled with
water. If the motor or the drum is blocked, the motor is energized after
the acceleration cycle. After a certain quantity of water has been
drained, contact 33 of the pressostat will close. At this very instant,
the blocking command occurs, to block the power supply and to
de-energize the motor. FIG. 3 shows that if the back-e.m.f. is zero,
transistor 18 is conducting and the circuit 18-19 through the tetrode
transistor of the device 6 (FIG. 2) supplies a voltage for blocking the
thyristors. Thus, when the motor is blocked full protection of the
motor, of the electronic circuitry and of the series resistor 3 (FIG. 2)
is provided, as long as the fault lasts, and any damage to these
elements of the machine is avoided.
FIG. 4 is a simplified
diagram of an embodiment of a control system for the rotation of the
motor of a washing machine in dependence on a plurality of operating
parameters.
The input terminal 27 of the reference voltage
generator 15 carries a rectified voltage equal to that produced by the
back-e.m.f. of the motor at a drum speed of 70 r.p.m. The input terminal
28 carries a rectified voltage which corresponds to a drum speed lower
than 50 r.p.m.

The machine is started with filled tub and closed
door, the pressostat 35 being in position 352 for the filled tub and the
door safety device 36 being in position 362 for the door closed; the
power supply 5 of the motor is then connected directly to the mains
terminal 1 and, through the motor resistance 3, to the mains terminal 2.
The washing water is heated by closing contact 37 of the timer. When
the water has not yet attained the desired temperature, the thermostat
38 remains in the cold position 381 and energizes the reference voltage
generator 15; since the motor has not yet begun the alternating washing
movement, its speed is lower than 50 rpm, thus causing the rectifier
bridge 5 to be cut off. The timer motor 39 which is also connected in
series with the thermostat 38 is not energized, and does not start until
the thermostat is in latter position 382; in this position terminal 28
is no longer energized, the back-e.m.f. of the motor is then higher than
the reference voltage and the normal power supply for the washing speed
is then applied to the motor terminals.
When door protection
contact 362 opens, the power supply of the rectifier bridge is
interrupted, which bridge constitutes the power supply 5 of the motor,
so that the motor is stopped. When the door is closed, the rectifier 5
is again energized by the closed contact 362. However, contact 361
closes again and applies a voltage to 27 which blocks the power supply.
Starting takes place after filling, upon closure of contact 352 of the
pressostat.

Protection against a blocked rotor is effected by the
disappearance of the back-e.m.f. of the motor. The reference voltage
generator 15, which is always energized via the terminal 27, will
therefore always have a voltage which is higher than the back-e.m.f. of
the motor, so that the power supply will be cut off when the tub is
empty and the motor is not rotating.
During spindrying the timer
contact 40 as well as the door protection contact 361 are closed. Since
this type of machine is started when the tub is filled with water, a
contact 41 allows the motor to speed up to spin-drying. After a very
short time, the pressostat 35 changes over to the empty-position 351 and
allows the terminal 27 of the rectified voltage generator 15 to be
energized.
The safety contact 42 for instability of the tub of
the machine, upon actuation, supplies a pulse which blocks the power
supply. Starting will take place after filling upon closure of contact
352 of the pressostat.

An automatic washing machine including a source ofelectric energy and a two-position safety switch. The en-ergizing winding of the water supply valve and the wind-ing of the drain pump motor are connected in series withone position of the safety switch across the energy source.A heating element and the drum motor winding are con-nected in parallel. This parallel combination is connectedin series with the second position_of the safety switchacross the energy source. The motor winding for the pro-gramming device is connected between the junction ofthe valve winding and the drain pump winding and thejunction of the second position of the safety switch withthe parallel combination of the heating element and thedrum -motor winding.

The present invention relates to an automatic washingmachine and, more particularly, to an improved program-ming device therefor. An electric washing and spin-dryingmachine generally comprises an electric circuit arrange-ment which feeds a programming device, a motor fordriving the drain pump and at least one motor for driv-ing the washing and spin-drying drum, a heating elementand an electromagnetically actuated water supply valvefor determining the water levels in the tub.

It is known that a machine for washing and spin-dryingcomprises one or twomotors each having one or morespeeds for the washing and spin-drying operations, amotor-driven pump and at least one heating element. Au-tomatic operation is made possible by the addition of anelectromagnetically actuated water supply valve and asafety device which controls the water levels required forwashing or rinsing. These various membersare controlledby, and in turn control, a programming device equippedwith a separate motor. In the known washing and spin-drying machines, the design of the circuits which includethe various electrical elements is such that the program-ming device must have a plurality of make-and-breakswitches, one in the circuit of each of the said. elements.

The inventionobviates this disadvantage and has for itsobject to provide a simpliﬁed programming device by theuse of a suitable design of the safety devices and of the cir-cuits which include the members which in cooperation per-form the washing and spin-drying operations. For this pur-pose the invention is characterized in that the circuit ar-rangement comprises two parallel branches, one of whichcomprises the series combination of a safety switch in theposition “ﬁlling,” the winding of the water supply valveand the winding of the drain-pump motor. The otherbranch comprises the series combination of the safetyswitch in the position “end of ﬁlling” and the parallel com-bination of the heating element and the windings of themotor or motors for driving the drum. The winding ofthe motor of the programming device is connected at oneend to the junction of the windings of the water supplyvalve and of the draining-pump motor and at the otherend to the junction of the safety switch in the position“end of ﬁlling” position and of the parallel combinationof the heating element and the driving motor.An advantageous embodiment of a washing machine inaccordance with the invention is characterized in thatthe impedances of the windings of the water-supply valveand the motor of the programming device are large com-pared with the impedances of the winding of the drain-pump motor and of the parallel combination comprisingthe heating element and the windings of the driving motoror motors.

A further feature of the washing machine in accordancewith the invention is that the safety switch in the position“ﬁlling” and the winding of the water-supply valve areshort-circuited through a contact of the programming de-vice.

A further feature is that the winding of the motor intended for the spin-drying operation is connected in serieswith the safety switch in the position “filling” and a make and break switch.

The invention will now be described more fully withreference of the accompanying drawing, the single ﬁgureof which shows the circuit diagram of a programming de-vice in accordance with the invention. During a wash-cyclethis programming device performs the following opera-tions: regulation of the Water level; rotation of the drumalternately in either direction in a rhythm which is deter-mined by a change-over switch which forms part of theprogramming device; and rapid rotation for spin-drying.

The cycle comprises the usual operations of a wash-pro-gramme, i.e. pre-washing with heating for a predeter-mined period of time, washing with heating for a pre-determined period of time, rinsing and, as the case maybe, drying by spinning.

Because in a wash-cycle both the washing quality andthe protection of the various machine parts must be takeninto account, the following measures are taken.

During the ﬁlling operation the programming device isinoperative and the machine is not started until the waterhas reached the correct level. Filling takes place onlywhen the pump is capable of normal operation, but can-not take place when the pump is disconnected or its wind-ings are switched off.The heating element cannot be switched on before thetub has been ﬁlled to the desired level. The reciprocatingmovement of the drum can only .be effected when the tubis ﬁlled, however, it continues during the draining operation until the water-level safety valve is actuated. Spindrying can only take place when the tub is empty of water.To prevent. a complete cycle from being performedduring the failure of an essential member, the machinestops: in the absence of water at the beginning of, or during,a cycle; when the heater is switched off or disconnected; and when the pump is switched off or disconnected.

This is ensured by a suitable design of the circuit ofthe motor of the programming device and by the action ofthe cams of this device on the switches of the various members.

A discussion of the operation will explain how a washcycle is effected.

The machine is energized from the supply line througha main switch having contacts 1 and 2. In the oIf—positionof the switch the entire machine is insulated from theelectric supply. Starting is effected by turning the knobof the programming device to the ﬁrst position so thatthe contacts 1 and 2 (or a single contact if there is amain switch at another point) are closed.

During the ﬁlling operation, a safety switch G is in theposition shown by a solid line, so that a water-supplyValve (not shown) is operative. A high-impedance WindingE of the valve now is connected in series with a low-impedance winding of a pump C. As a result of the volt-age divider effect the voltage across the pump winding is very small so that the motor F of the programmingdevice, in parallel therewith, is not driven. The voltageacross the heater element D, in series with motor windingF, is so low that it can be considered to be negligible.

When the correct water level is reached, the safetyswitch G passes from the -position shown by the solid lineto the position shown by the broken line. The heatingelement D and a washing motor A now are energized, thelatter through one of the positions of a change-overswitch H. The motor of the programming device F is nowenergized through the windings of the pump C so that itcan run. The machine then performs the wash-cycle, thedrum being rotated alternately in either direction. In orderto begin the draining operation, a contact 3 of the pro-gramming device is closed. The motor of the programmingdevice F is stopped because it is short-circuited throughthe switch 3 and the switch G. When the water drops toa given level, the switch G changes position, i.e., passesfrom the position shown by the broken line to the posi-tion shown by the solid line, thereby removing the shortcircuit from winding F. The motor of the programmingdevice now is energized through the switch 3, the heatingelement D and the windings of the washing motor A.Since the switch 3 is closed, the winding E is short cir-cuited. When the heating element is switched off, themotor of the programming device will stop as soon asthe change-over switch H of the washing motor A passesfrom one position to the other. The pump C alone re-mains operative and the machine stops.

On termination of the draining operation, i.e., whenthe tub is empty, the contact 4 is closed to start the spin-drying cycle. The spin motor B then is energized throughcontact 4 and the safety switch G, which is in the posi-tion shown by the solid line.

The cycle is terminated by opening the contacts 1 and2 after the last spin-drying operation.

What is claimed is:

1. An automatic electric washing machine comprising,an electric circuit arrangement for energizing the motorof a programming device, a motor for driving the drainpump, at least one motor for driving the drum, a heatingelement and the winding of an electromagnetically actu-ated water level supply valve, and a safety switch havingﬁrst and second positions corresponding to a Water ﬁllingcondition and an end of ﬁlling condition, respectively, thecircuit arrangement comprising two parallel branchescoupled to a source of electric energy, one branch com-prising the series combination of the safety switch in theﬁrst position, the winding of the water supply valve andthe winding of the pump motor, the other branch com-prising the series combination of the safety switch in thesecond position and the parallel combination of the heat-ing element and the windings of the drum motor, meansconnecting one end of the motor winding of the pro-gramming device to the junction of the windings of thewater supply valve and of the pump motor and the otherend to the junction of the safety switch in the secondposition and the parallel combination of the heating ele-ment and the drum motor winding.

2. A washing machine as claimed in claim 1 whereinthe impedances of the windings of the water-supply valveand of the motor of the programming device are largerelative to the impedances of the winding of the pumpmotor and of the parallel combination comprising theheating element and the windings of the drum motor.

3. A washing machine as claimed in claim 1 whereinthe programming device includes a switching contactconnected in shunt with the series combination of thesafety switch in the ﬁrst position and the winding of thewater-supply valve.

4. A washing machine as claimed in claim 1 furthercomprising a make-and-break switch and a winding fordriving the drum motor at high speed during the spin-drycycle, and means connecting said high speed motor wind-ing in series with the safety switch in the ﬁrst positionand the make-and-break switch.

5. An automatic washing machine comprising a waterlevel safety switch adapted to switch between ﬁrst andsecond positions as a function of the water level in themachine, a source of electric energy, an electromagnetwinding for controlling the water supply valve, a windingfor the drain pump motor, means serially connecting thesafety switch in the ﬁrst position, the electromagnet wind-ing and the pump motor winding across said energysource, a heater element and a winding for driving thedrum motor connected in parallel, means connectingthe safety switch in the second position in series with theparallel combination of the heater element and the drum-motor winding across said energy source, a winding forthe motor of the machine programming device, meansconnecting one end of the programming motor windingto the junction of the electromagnet winding and thepump motor winding, and means connecting the other endof the programming motor winding to the junction of thesafety switch in the second position with said parallelcombination.

6. A washing machine as claimed in claim 5 whereinthe impedance of the electromagnet winding and the im-pedance of the programming motor winding are each sub-stantially greater than the impedance of the pump motorwinding.

7. A washing machine as claimed in claim 6 whereinsaid programming device includes a switch contact con-nected in shunt with the electromagnet winding via theﬁrst position of the safety switch and in series with thepump motor winding across said energy source.

8. A washing machine as claimed in claim 7 furthercomprising a winding for driving the drum motor at highspeed to produce a spin-drying cycle, a switch, and meansconnecting said high speed winding, said switch, and thesafety switch in the ﬁrst position in series circuit acrosssaid energy source.

IGNIS K12 (PHILIPS) AWF627/IG P.M. SYSTEM PUSHBUTTON SWITCH:

Pushbutton switch which has a single housing both forthe mechanical operation of the pushbuttons and also forcarrying the electrical contacts and slides.

The invention relates to pushbutton switches of the kindhaving a housing for the mechanical operation of thepushbuttons and one or more carriers for electrical con-tacts.Existing pushbutton switches of this kind have twoseparate housings, one for mechanical operation, that isto say for the control of pushbutton slides, for mechani-cal locking and so forth, and the other as an added con-tact housing to carry the electrical contacts. This makesthem rather expensive and bulky, large numbers of com-ponents, particularly stamped-out parts, having to be used.In some cases, too, the pushbutton slides and catch slidesare assembled in two parts, so that assembly is also com-plicated, especially as, in this known kind of pushbuttonswitch, the button-slide levers are at right angles to theplane of the catch slides.

An object of the invention is to eliminate these draw-backs and to provide a pushbutton switch of the kind de-scribed, which is of simple design, less expensive andoccupies less space than known pushbutton switches.

According to the present invention there is provided apushbutton switch of the kind having a housing for themechanical operation of the pushbuttons and one or morecarriers for electrical contacts, wherein the housing com-prises two plates of insulating material, which serve tocontrol the pushbutton slides and to carry the electricalcontacts.

In this way, only a single housing is required, to meetboth the mechanical and the electrical requirements ofthe pushbutton switch. The pushbutton switch conform-ing to the invention thus makes it possible to dispensewith many of the parts used hitherto.

Another feature of the invention is that the carrier forthe electrical contacts consists of at least one baseplatecontaining slots into which the contacts can be inserted.Among other advantages, this facilitates assembly, sincethe insertion of the contacts is extremely easy and can becarried out quickly. Two such contact plates should pref-erably be provided, through which the contacts are in-serted.

In that case, according to a further advantageous fea-ture of the invention, pushbutton slides can be ﬁtted withtags and springs, resulting in springy contacts that areeasy to ﬁt and remove. Moreover, one of the two base-plates may well serve as a stop for the pushbutton slide.This makes it unnecessary to ﬁt a separate stop, so thatin this respect, too, the pushbutton switch is simpler, andfewer possible components are used which simpliﬁes theirassembly.

Another feature of the invention provides for the catchslides to be carried in slots in the housing frame.

A particularly advantageous feature of the inventionis that both the plates of insulating material alreadymentioned are gripped in a frame forming three sides ofthe housing, the ﬁxing plate being ﬂanged on to thisframe. Because the frame is U-shaped, the other ﬁxingplate does not require any shaping, which naturally rep-resents further simpliﬁcation in manufacture. The frontﬁxing plate may be riveted or welded to the other, curved,plate. With a frame of ﬂanged design, it is also possibleto use screws for assembly.

The invention will be further described by way of ex-ample with reference to the accompanying diagrammaticdrawings, in which:

FIGURE 1 is a plan of pushbutton switch accordingto the invention, with the top plate removed;

FIGURE 2 is a vertical section taken along the lineA—B in FIGURE 1, with a top plate;

FIGURE 3 is an underneath plan view of the push-button switch illustrated in FIGURES 1 and 2;

FIGURE 4 is a similar view to FIGURE 3, but witha baseplate ﬁtted; and

FIGURE 5 is a front View of the pushbutton switch.

Referring to the drawings in detail FIGURES 1 and 2show two plates of insulating material, 1 and 2, whichserve to carry a number of pushbutton slides 5. As can beseen, the pushbutton slides 5 are ﬁtted to slide at theirfront ends in the plate 1 and at their rear ends in the plate2. The plate 2 is bent to form a U and is provided witha ﬂange to which the plate 1 is riveted. The contacts aremerely represented diagrammatically in position; in fact,as will be described hereinafter, they are inserted (seeFIGURE 2) in slots in the baseplate 6.

FIGURE 2 also shows a top plate 11, having slotsthrough which the contacts 8 are likewise inserted. Ascan be seen from FIGURES 1 and 2, each pushbuttonslide 5 is ﬁtted with tags 9 and springs 10. The baseplate6 is formed with a front extension which extends beyondthe plate of insulating material 1, to act as a stop for thepushbutton slide 5 provided with a nose-like projection,14, which engages the extension when the pushbuttonslide 5 is pushed in.

A return spring, 12, is ﬁtted in the pushbutton slide 5,which restores the pushbutton slide 5 to its inoperativeposition as illustrated in FIGURE 2.

FIGURE 3 shows, two catch slides 3 and 4 which aremounted in the plate of insulating material 2. Two of thepushbutton slides 5 mounted on the catch slide 3 have astop to ensure that operation is not possible until twoother pushbutton slides 5 have been pressed. The othercatch slide 4, has no cam projection at one button, toensure that when this button is pressed the adjacent onedoes not spring out. The travel is the same for all thebuttons. Contacts may be provided as desired, i.e. break,make, or change-over contacts. The depth of the push-button slide according to the invention is equivalent to thewidth of the two catch slides 3 and 4. The height is deter-mined by the width required to accommodate the buttonslides and catch slides combined, because these work inparallel planes and not, as in known pushbutton slides,at right angles to each other, which saves a considerableamount of space.

The contacts 8 are all made up as units and can beplugged in, as already stated. Thus, all that is needed isa single movement to set up the contact studs in differentpositions. The contacts 8 can be stamped out very eco-nomically. The pushbutton slides 5 themselves are madein one piece, preferably by press or injection moulding.

When the pushbutton switch is used for washing ma-chines, it is sutﬁcient, apart from the Off-button, i.e. thelarger button 5 (see FIGURE 3), to provide four selectorbuttons suitable for all programmes. The “Off” buttonshould preferably be coloured red, and when operated itreleases all the buttons and remains in the “Oif” position,in which the head of the button is aligned with all theother buttons. The mode of operation of the rest of thebuttons will be apparent from ‘FIGURE 3.

FIGURE 4 shows, in particular, the baseplate 6 con-taining slots 7 for the contacts 8, while FIGURE 5 serves,more particularly, to show the dimensions of the frontplate 1 of insulating material, and the holes 15 for rivet-ing the plate '1 to the plate of insulating material 2 ashereinbefore, described. FIGURE 3 also makes clear howthe pushbuttons 5 areguided by the front plate 1. Inaddition, the plates 6 and 11 (see also FIGURE 2) areheld directly by the plates of insulating material 1 and 2,resulting in the simpliﬁcation of the switch constructionalready mentioned.

The manufacture and assembly of the switch is par-ticularly simple, in that the contacts 8 are inserted intothe parallel slots 7 in the baseplate 6 and the pushbuttonslides 5, ﬁtted with their tags 9 and springs 10, are placedin position. Then the top plate 11 is ﬁtted in position overthe «contacts 8, likewise ‘by their corresponding slots, andthe shoulders of the contacts 8 are bent over or set at anangle to secure the plates 6 and 11 to each other. Thisbending or setting of the contacts 8 is necessary only inrespect of two or three contacts 8 located in the middleof the plates. A U-shaped member which is also known asthe “chassis” is then pushed into position and the frontplate 1 is riveted or welded to it. The compression springs12 are then inserted into the recesses provided for them.To prevent these springs from dropping out, a safety plate16 (see FIGURE 2) is provided. Finally, the catchslides )3 and 4 are inserted; these can .readily be replaced sub-sequently by others. The stop by which the travel of thepushbutton slides 5 is limited, is located in the recess forthe return springs 12, and also prevents the pushbuttons5 from jumping out of the front plate 1.

What ‘I claim is:

1. A pushbutton switch comprising a substantially U-shaped ﬁrst member of insulating material, said membercomprising a bottom portion, integral side portions andﬂange portions extending outwardly from the ends of saidside portions, a second member of insulating materialsecured to said ﬁrst memberpand closing off the top thereof, said bottom portion of said ﬁrst member and said sec-ond member respectively being provided with alignedslots, a plurality of pushbutton slides carried in said slotsin said members, third and fourth members spaced fromone another, carried by said ﬁrst and second membersand having said slides positioned therebetween, a plurality of contacts carried by said third and fourth memberssaid pushbuttons slides carrying spring biased tags, meanswhereby said tags engage said contacts, and at least onecatch slide being operatively engaged with at least someof said pushbutton slides and ‘being carried and slidinglyengaged by said ﬁrst member.

2. The pushbutton switch of claim 1 wherein said atleast one catch slide extends transversely to said push-button slides and being slidably carried by said side por-tions of said ﬁrst member.

3. The pushbutton switch of claim 1 wherein said ﬁrstand second members are secured together by riveting.

4. The pushbutton slide of claim 1 wherein said ﬁrstand second members are secured together by welding.

5. The pushbutton switch of claim 1 wherein said thirdand fourth members are provided with aligned slotsthrough which said contacts extend and wherein at leastsome of said contacts are bent ‘beyond the outer faces ofsaid members in order to secure said members together.

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IMPORTANT NOTE: - FRANK SHARP washingmachinesmuseum.blogspot.com was founded as a public WEB Museum to amateur and professional Washing Machines Lovers who enjoy using and/or preserving - restoring vintage Washing machinery. The purpose is to provide information about vintage machinery that is generally difficult to locate. washingmachinesmuseum.blogspot.com does not provide support or parts for any machines on this site nor do we represent any manufacturer listed on this site in any way. Catalogs, manuals and any other literature that is available on this site is made available for a historical record only. Please remember that safety standards have changed over the years and information in old manuals as well as the old machines themselves may not meet modern standards. It is up to the individual user to use good judgment and to safely operate old machinery. The washingmachinesmuseum.blogspot.com web site will assume no responsibilities for damages or injuries resulting from information obtained from this site.

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Electrical Appliances Safety Hazards:

On any given day, it's likely that most people use several different electrical appliances. With electric appliances being so common in modern homes, it's easy to forget that there are very real risks and hazards associated with their use. Take the time to brush up on the principles of safe operation - and make sure that everyone in your home is aware of them - in order prevent unnecessary exposure to hazards and safety risks.

Being safe when using electrical appliances, extension cords, light bulbs and other equipment is easy, and safety tips should be included in household rules, homeschool fire safety and daily behavior expectations for all members of the family. It only takes one mistake to spark an electrical fire, but simple prevention measures can be effective solutions.

Appliances:

Appliances are an integral part of every household, from a simple electric clock to the microwave oven. These safety tips can help keep all appliances operating safely:

It's essential to ensure that any appliances you purchase are approved. Unplug unused appliances and stow cords safely out of reach of pets, young children or hazardous situations. Electric Stove Repair Appliances that generate heat, such as clocks, televisions and computer monitors, should be given several inches of clearance all around for good air circulation and cooling. Do not drape clothes, toys or other items over warm appliances. Always follow appliance instructions carefully, and do not attempt amateur repairs or upgrades. Keep all electrical appliances away from water such as sinks, bathtubs, pools or overhead vents that may drip. Do not operate any electrical appliance with wet hands or while standing in water. Keep clothes, curtains, toys and other potentially combustible materials at away from radiators, space heaters, heating vents and other heat sources.

Cords

Every electrical appliance has a cord, and many homes use extension cords to increase the range of electrical outlets. These safety tips can help keep cords in good condition for safe operation:

Check cords regularly for frays, cracks or kinks, including power tool cords, holiday lights and extension cords. Safety suggests doing this before each use.

Cords are not jump ropes, clothes lines or leashes, and should never be used for anything other than their intended purpose. Cords should be firmly plugged into outlets - if the cord is loose and can pull out easily, choose a different, more snug outlet. Do not staple or nail cords in position at any time; if the cord does not remain where desired, use tape or twist ties to secure it. Cords should not be placed beneath rugs where they can become a trip hazard or where frays will not be noticeable. Furthermore, covering a cord will prevent it from keeping as cool as possible. Do not make modifications to a cord's plug at any time - do not clip off the third prong or attempt to file down a wider prong to fit in a different outlet. Extension cords are a temporary solution only, and their use should be minimized whenever possible. Use the proper weight and length of extension cord for the appropriate task, and be sure the cord is rated for indoor or outdoor use, whichever is required. When unplugging a cord, pull on the cord at the outlet rather than tug on the cord itself.

Outlets:

Every cord has to plug into an appropriate electrical outlet, but these tempting niches are inviting to unwelcome objects that can cause shorts and fires. Use these electrical safety tips at home to keep outlets safe.

Block unused outlets by changing to a solid cover plate or using childproof caps.

Do not overload outlets with multiple adaptors or power strips; relocate cords instead.Never put any object other than the appropriate size plug into an outlet.Install ground fault circuit interrupter outlets in potentially hazardous areas such as near pools, crawl spaces, kitchens, bathrooms and unfinished basements.Keep all outlets properly covered with secure plates that cover all wiring.

When an electrical short or spark does happen, it is vital to understand what to do to prevent or put out an electrical fire to keep the damage and devastation from spreading. You should, of course, call 911 or other appropriate emergency services immediately in case of electrical injury or fire.

Do not allow children to play in proximity to small or large electric appliances.Replace any tools that put off even mild electric shocks.Replace any light switches that have a tendency to flicker.Replace any light switches that are hot to the touch.Avoid overloading extension cords, sockets and plugs.Do not every force a three-prong plug into a two-receptacle socket.Know where fuse boxes and circuit breakers are located as well as how to properly operate them.Never attempt electrical repairs or rewiring without proper certification and experience.Do not put water on an electrical fire; use a dry fire extinguisher or baking soda instead.

SAFETY guidelines:

Appliance repair Convenient and SAFE.

Many people do not realize that malfunctioning equipment can pose serious risks to their health and safety.

Prompt, professional appliance repair can help you avoid disaster, injury, and disease.

If you’ve been putting off repairing household appliances, you should know that this does not mean only inconvenience but could be dangerous as well.

Check your home for the following electrical hazards:

Frayed or worn electric cords Appliance plugs “piggy backed” on a single switch Electrical appliances such as radios, hairdryers, shavers, portable lamps, or radiators used near showers, baths or swimming pools Extension cords being used instead of permanent indoor/outdoor wiring Wet floors are present where electricity is used Electrical appliances that blow fuses, overheat, or spark heavily

The best way to reduce the risk of death from electric shock at home is to have a safety switch, called a residual current device (RCD), fitted within your household fuse box. If there is faulty or wet wiring, or any electric current passing through a person, the safety switch will cut off the power within a fraction of a second. While the safety switch is not guaranteed to stop an electrical shock, it is guaranteed to make the injury much less serious.

Turn off electrical hazards in your home permanently by avoiding the following:

Have a licensed electrician install a safety switch inside the house to replace your external fuse box. Frayed, worn, or damaged cords and extension cords should not be repaired with tape—throw them out. Always turn an appliance off before unplugging it. When unplugging an appliance, make sure to hold the plug and not the cord. Turn small appliances off when not in use. Make sure outdoor appliances don’t come into contact with pools or puddles of water. When using electricity in wet areas, always wear rubber sole shoes. Never touch appliances or switches with wet hands. Never fold or crumple an electric blanket. Call a licensed electrician for any repairs needed to switches, power points, or light fittings. Send faulty appliances to be repaired or throw them out. Don’t attempt to repair them yourself unless you are qualified. Use plug-in covers to prevent children from poking objects into power points. Make sure to unplug electrical appliances after using them.

Make sure to place electrical appliances where children are unable to reach them.

By procrastinating, you could be putting your personal safety at risk in a number of ways by leaving yourself vulnerable to:

Slipping hazards: Sudden puddles on the floor are commonplace in homes that require dishwasher repair or washing machine repair.

These pools could be due to poor door seals, clogged drains, problems with water supply and drainage and other problems – only an expert can say with certainty.

Fire hazards and gas leaks: Sparking microwaves, electrical shocks, an oven that’s hot to the touch–there are a lot of hazards that can arise when heat-based appliances start to act out.

Gas leak of deadly serious house fire, these are some of the deadliest threats to fight a family – and can happen at the drop of a hat.

Pick up the phone and call a pro the moment that you suspect you require oven repair, dryer repair, or other repairs.

Health risks: refrigerators to help keep food fresh, but if they begin with the maintenance of proper cool fight, the food tends to spoil faster.

Food poisoning is an often-forgotten but very real threat to personal health.

Save yourself the pain and the fight against sub-standard quality of service refrigerator.

In additional to the aforementioned hazards, appliances that do not properly handle water can threaten personal health by harboring pathogens and encouraging mold growth in your home.

Both scenarios can lead to serious illness and even death in some cases.

That’s a big price to pay for just letting your appliances go unrepaired!

Malfunctioning appliances could be the result of poor initial installation, wear and tear from years of heavy use, or sudden damages.

It does not matter, the cause of your machine to crash, it is advisable to hire professional help as soon as you find a problem.

Remember, repairs aren’t always about convenience–they’re also about protection.

The most serious or fatal accidents in and around the house, so it is important that you take all threats immediately apparent.

Your local experts will have the tools and know-how to diagnose your problem and put a stop to it so you can continue to enjoy a safe home.

The man who does not exercise the first law of nature—that of self preservation — is not worthy of living and breathing the breath of life.

We now live in a nation where doctors destroy health, lawyers destroy justice, universities destroy knowledge, governments destroy freedom, the press destroys information, religion destroys morals and our banks destroy the economy.The globalist argument is that if only we erase distinctions, obliterate identities, put everyone on a level playing field, etc.. we can eliminate war and everyone can be so prosperous and efficient, such great cogs in a well-oiled global machine.There will be no more historical grievances because people will no longer even care, they'll have no connection to the past, no foolish pride in past accomplishments of people totally unrelated to them.A globalized culture, no borders, everyone a citizen of the world.Know this: I will never acquiesce to this corrupt, inhuman, Borg-like vision. The dangerous lunatics who push us towards their globalized "utopia" are my enemy. How exactly all this will play out, whether through wars, or whether we can thwart the globalist agenda peacefully (this is my hope of course) I don't know. But I do know that unless people are willing to fight and die, globalism will win out in the end.The actual crimes committed by the EU against the European peoples are directly in violation of the 1948 UN genocide convention, Article II: (c) Deliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part; (d) Imposing measures intended to prevent births within the group; (e) Forcibly transferring children of the group to another group.

* The man who does not exercise the first law of nature—that of self preservation — is not worthy of living and breathing the breath of life.